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FFmpeg/libavformat/nut.c

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  1. /*

  2.  * "NUT" Container Format muxer and demuxer (DRAFT-200403??)

  3.  * Copyright (c) 2003 Alex Beregszaszi

  4.  * Copyright (c) 2004 Michael Niedermayer

  5.  *

  6.  * This library is free software; you can redistribute it and/or

  7.  * modify it under the terms of the GNU Lesser General Public

  8.  * License as published by the Free Software Foundation; either

  9.  * version 2 of the License, or (at your option) any later version.

  10.  *

  11.  * This library is distributed in the hope that it will be useful,

  12.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  13.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  14.  * Lesser General Public License for more details.

  15.  *

  16.  * You should have received a copy of the GNU General Public

  17.  * License along with this library; if not, write to the Free Software

  18.  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  19.  *

  20.  * NUT DRAFT can be found in MPlayer CVS at DOCS/tech/mpcf.txt

  21.  *

  22.  * AND http://people.fsn.hu/~alex/nut/ (TeX, pdf, ps, dvi, ..)

  23.  *

  24.  */

  25. 

  26. /*

  27.  * TODO:

  28.  * - index writing

  29.  * - index packet reading support

  30. */

  31. 

  32. //#define DEBUG 1

  33. 

  34. #include <limits.h>

  35. #include "avformat.h"

  36. #include "mpegaudio.h"

  37. #include "avi.h"

  38. 

  39. #undef NDEBUG

  40. #include <assert.h>

  41. 

  42. //from /dev/random

  43. 

  44. #define     MAIN_STARTCODE (0x7A561F5F04ADULL + (((uint64_t)('N'<<8) + 'M')<<48)) 

  45. #define   STREAM_STARTCODE (0x11405BF2F9DBULL + (((uint64_t)('N'<<8) + 'S')<<48)) 

  46. #define KEYFRAME_STARTCODE (0xE4ADEECA4569ULL + (((uint64_t)('N'<<8) + 'K')<<48)) 

  47. #define    INDEX_STARTCODE (0xDD672F23E64EULL + (((uint64_t)('N'<<8) + 'X')<<48)) 

  48. #define     INFO_STARTCODE (0xAB68B596BA78ULL + (((uint64_t)('N'<<8) + 'I')<<48)) 

  49. 

  50. #define MAX_TYPE1_DISTANCE (1024*16-1)

  51. #define MAX_TYPE2_DISTANCE (1024*64-1)

  52. 

  53. #define MAX_SIZE_LRU 2

  54. #define MAX_PTS_LRU 3

  55. 

  56. #define FLAG_FRAME_TYPE      1

  57. #define FLAG_DATA_SIZE       2

  58. #define FLAG_PTS            16

  59. #define FLAG_FULL_PTS        4

  60. #define FLAG_KEY_FRAME      32

  61. 

  62. typedef struct {

  63.     uint8_t flags;

  64.     uint8_t stream_id_plus1;

  65.     uint8_t size_mul;

  66.     uint8_t size_lsb;

  67. } FrameCode;

  68. 

  69. typedef struct {

  70.     int last_key_frame;

  71.     int msb_timestamp_shift;

  72.     int rate_num;

  73.     int rate_den;

  74.     int64_t last_pts;

  75.     int64_t last_full_pts;

  76.     int lru_pts_delta[MAX_PTS_LRU];

  77.     int lru_size[MAX_SIZE_LRU];

  78.     int initial_pts_predictor[MAX_PTS_LRU];

  79.     int initial_size_predictor[MAX_SIZE_LRU];

  80.     int64_t last_sync_pos;                    ///<pos of last 1/2 type frame

  81. } StreamContext;

  82. 

  83. typedef struct {

  84.     AVFormatContext *avf;

  85.     int64_t packet_start;

  86.     int64_t last_packet_start;

  87.     int written_packet_size;

  88.     int64_t packet_size_pos;

  89.     int64_t last_frame_start[3];

  90.     FrameCode frame_code[256];

  91.     int stream_count;

  92.     uint64_t next_startcode;     ///< stores the next startcode if it has alraedy been parsed but the stream isnt seekable

  93.     StreamContext *stream;

  94. } NUTContext;

  95. 

  96. static char *info_table[][2]={

  97. 	{NULL			,  NULL }, // end

  98. 	{NULL			,  NULL },

  99. 	{NULL			, "UTF8"},

  100. 	{NULL			, "v"},

  101. 	{NULL			, "s"},

  102. 	{"StreamId"		, "v"},

  103. 	{"SegmentId"		, "v"},

  104. 	{"StartTimestamp"	, "v"},

  105. 	{"EndTimestamp"		, "v"},

  106. 	{"Author"		, "UTF8"},

  107. 	{"Title"		, "UTF8"},

  108. 	{"Description"		, "UTF8"},

  109. 	{"Copyright"		, "UTF8"},

  110. 	{"Encoder"		, "UTF8"},

  111. 	{"Keyword"		, "UTF8"},

  112. 	{"Cover"		, "JPEG"},

  113. 	{"Cover"		, "PNG"},

  114. };

  115. 

  116. static void update_lru(int *lru, int current, int count){

  117.     int i;

  118. 

  119.     for(i=0; i<count-1; i++){

  120.         if(lru[i] == current)

  121.             break;

  122.     }

  123. 

  124.     for(; i; i--){

  125.         lru[i]= lru[i-1];

  126.     }

  127. 

  128.     lru[0]= current;

  129. }

  130. 

  131. static void update(NUTContext *nut, int stream_index, int64_t frame_start, int frame_type, int frame_code, int key_frame, int size, int64_t pts){

  132.     StreamContext *stream= &nut->stream[stream_index];

  133.     const int flags=nut->frame_code[frame_code].flags; 

  134.     

  135.     stream->last_key_frame= key_frame;

  136.     nut->last_frame_start[ frame_type ]= frame_start;

  137.     if(frame_type == 0)

  138.         update_lru(stream->lru_pts_delta, pts - stream->last_pts, 3);

  139.     update_lru(stream->lru_size, size, 2);

  140.     stream->last_pts= pts;

  141.     if((flags & FLAG_PTS) && (flags & FLAG_FULL_PTS))

  142.         stream->last_full_pts= pts;

  143. }

  144. 

  145. static void reset(AVFormatContext *s/*, int frame_type*/){

  146.     NUTContext *nut = s->priv_data;

  147.     int i;

  148.     

  149.     for(i=0; i<s->nb_streams; i++){

  150.         StreamContext *stream= &nut->stream[i];

  151.     

  152.         stream->last_key_frame= 1;

  153.         memcpy(stream->lru_pts_delta, stream->initial_pts_predictor, sizeof(int)*MAX_PTS_LRU);

  154.         memcpy(stream->lru_size, stream->initial_size_predictor, sizeof(int)*MAX_SIZE_LRU);

  155.     }

  156. }

  157. 

  158. static void build_frame_code(AVFormatContext *s){

  159.     NUTContext *nut = s->priv_data;

  160.     int key_frame, frame_type, full_pts, index, pred, stream_id;

  161.     int start=0;

  162.     int end= 255;

  163.     int keyframe_0_esc= s->nb_streams > 2;

  164. 

  165.     if(keyframe_0_esc){

  166.         /* keyframe = 0 escapes, 3 codes */

  167.         for(frame_type=0; frame_type<2; frame_type++){

  168.             for(full_pts=frame_type; full_pts<2; full_pts++){

  169.                 FrameCode *ft= &nut->frame_code[start];

  170.                 ft->flags= FLAG_FRAME_TYPE*frame_type + FLAG_FULL_PTS*full_pts;

  171.                 ft->flags|= FLAG_DATA_SIZE | FLAG_PTS; 

  172.                 ft->stream_id_plus1= 0;

  173.                 ft->size_mul=1;

  174.                 start++;

  175.             }

  176.         }

  177.     }

  178. 

  179.     for(stream_id= 0; stream_id<s->nb_streams; stream_id++){

  180.         int start2= start + (end-start)*stream_id / s->nb_streams;

  181.         int end2  = start + (end-start)*(stream_id+1) / s->nb_streams;

  182.         AVCodecContext *codec = &s->streams[stream_id]->codec;

  183.         int is_audio= codec->codec_type == CODEC_TYPE_AUDIO;

  184.         int intra_only= /*codec->intra_only || */is_audio;

  185.         int pred_count;

  186. 

  187.         for(key_frame=0; key_frame<2; key_frame++){

  188.             if(intra_only && keyframe_0_esc && key_frame==0)

  189.                 continue;

  190.             

  191.             for(frame_type=0; frame_type<2; frame_type++){

  192.                 for(full_pts=frame_type; full_pts<2; full_pts++){

  193.                     FrameCode *ft= &nut->frame_code[start2];

  194.                     ft->flags= FLAG_FRAME_TYPE*frame_type + FLAG_FULL_PTS*full_pts + FLAG_KEY_FRAME*key_frame;

  195.                     ft->flags|= FLAG_DATA_SIZE | FLAG_PTS;

  196.                     ft->stream_id_plus1= stream_id + 1;

  197.                     ft->size_mul=1;

  198.                     start2++;

  199.                 }

  200.             }

  201.         }

  202. 

  203.         key_frame= intra_only;

  204. #if 1

  205.         if(is_audio){

  206.             int frame_bytes= codec->frame_size*(int64_t)codec->bit_rate / (8*codec->sample_rate);

  207.             for(pred=0; pred<MAX_SIZE_LRU; pred++){

  208.                 for(frame_type=0; frame_type<1; frame_type++){

  209.                     FrameCode *ft= &nut->frame_code[start2];

  210.                     ft->flags= FLAG_KEY_FRAME*key_frame + (FLAG_FULL_PTS+FLAG_PTS+FLAG_FRAME_TYPE)*frame_type;

  211.                     ft->stream_id_plus1= stream_id + 1;

  212.                     ft->size_mul=1;

  213.                     ft->size_lsb=1 + pred;

  214.                     start2++;

  215.                 }

  216.                 nut->stream[stream_id].initial_size_predictor[pred]= frame_bytes + pred;

  217.             }

  218.         }else{

  219.             FrameCode *ft= &nut->frame_code[start2];

  220.             ft->flags= FLAG_KEY_FRAME | FLAG_DATA_SIZE;

  221.             ft->stream_id_plus1= stream_id + 1;

  222.             ft->size_mul=1;

  223.             start2++;

  224.         }

  225. #endif

  226.         pred_count= 2 + codec->has_b_frames + (codec->codec_id == CODEC_ID_VORBIS);

  227.         for(pred=0; pred<pred_count; pred++){

  228.             int start3= start2 + (end2-start2)*pred / pred_count;

  229.             int end3  = start2 + (end2-start2)*(pred+1) / pred_count;

  230. 

  231.             for(index=start3; index<end3; index++){

  232.                 FrameCode *ft= &nut->frame_code[index];

  233.                 ft->flags= FLAG_KEY_FRAME*key_frame + pred*4;

  234.                 ft->flags|= FLAG_DATA_SIZE;

  235.                 ft->stream_id_plus1= stream_id + 1;

  236. //FIXME use single byte size and pred from last

  237.                 ft->size_mul= end3-start3;

  238.                 ft->size_lsb= index - start3;

  239.             }

  240.             nut->stream[stream_id].initial_pts_predictor[pred]= pred+1;

  241.         }

  242.     }

  243.     memmove(&nut->frame_code['N'+1], &nut->frame_code['N'], sizeof(FrameCode)*(255-'N'));

  244.     nut->frame_code['N'].flags= 1;

  245. }

  246. 

  247. static uint64_t get_v(ByteIOContext *bc)

  248. {

  249.     uint64_t val = 0;

  250. 

  251.     for(;;)

  252.     {

  253. 	int tmp = get_byte(bc);

  254. 

  255. 	if (tmp&0x80)

  256. 	    val= (val<<7) + tmp - 0x80;

  257. 	else

  258. 	    return (val<<7) + tmp;

  259.     }

  260.     return -1;

  261. }

  262. 

  263. static int get_str(ByteIOContext *bc, char *string, int maxlen){

  264.     int len= get_v(bc);

  265.     

  266.     if(len && maxlen)

  267.         get_buffer(bc, string, FFMIN(len, maxlen));

  268.     while(len > maxlen){

  269.         get_byte(bc);

  270.         len--;

  271.     }

  272. 

  273.     if(maxlen)

  274.         string[FFMIN(len, maxlen-1)]= 0;

  275.     

  276.     if(maxlen == len)

  277.         return -1;

  278.     else

  279.         return 0;

  280. }

  281. 

  282. static uint64_t get_vb(ByteIOContext *bc){

  283.     uint64_t val=0;

  284.     int i= get_v(bc);

  285.     

  286.     if(i>8)

  287.         return UINT64_MAX;

  288.     

  289.     while(i--)

  290.         val = (val<<8) + get_byte(bc);

  291.     

  292.     return val;

  293. }

  294. 

  295. static int get_packetheader(NUTContext *nut, ByteIOContext *bc, int prefix_length, int calculate_checksum)

  296. {

  297.     int64_t start, size, last_size;

  298.     start= url_ftell(bc) - prefix_length;

  299. 

  300.     if(nut->written_packet_size >= 0 && start != nut->packet_start + nut->written_packet_size){

  301.         av_log(nut->avf, AV_LOG_ERROR, "get_packetheader called at weird position\n");

  302.         if(prefix_length<8)

  303.             return -1;

  304.     }

  305.     

  306.     init_checksum(bc, calculate_checksum ? update_adler32 : NULL, 0);

  307. 

  308.     size= get_v(bc);

  309.     last_size= get_v(bc);

  310.     if(nut->written_packet_size >= 0 && nut->written_packet_size != last_size){

  311.         av_log(nut->avf, AV_LOG_ERROR, "packet size missmatch %d != %lld at %lld\n", nut->written_packet_size, last_size, start);

  312.         if(prefix_length<8)

  313.             return -1;

  314.     }

  315. 

  316.     nut->last_packet_start = nut->packet_start;

  317.     nut->packet_start = start;

  318.     nut->written_packet_size= size;

  319. 

  320.     return size;

  321. }

  322. 

  323. static int check_checksum(ByteIOContext *bc){

  324.     unsigned long checksum= get_checksum(bc);

  325.     return checksum != get_be32(bc);

  326. }

  327. 

  328. /**

  329.  * 

  330.  */

  331. static int get_length(uint64_t val){

  332.     int i;

  333. 

  334.     for (i=7; val>>i; i+=7);

  335. 

  336.     return i;

  337. }

  338. 

  339. static uint64_t find_any_startcode(ByteIOContext *bc, int64_t pos){

  340.     uint64_t state=0;

  341.     

  342.     if(pos >= 0)

  343.         url_fseek(bc, pos, SEEK_SET); //note, this may fail if the stream isnt seekable, but that shouldnt matter, as in this case we simply start where we are currently

  344. 

  345.     while(!url_feof(bc)){

  346.         state= (state<<8) | get_byte(bc);

  347.         if((state>>56) != 'N')

  348.             continue;

  349.         switch(state){

  350.         case MAIN_STARTCODE:

  351.         case STREAM_STARTCODE:

  352.         case KEYFRAME_STARTCODE:

  353.         case INFO_STARTCODE:

  354.         case INDEX_STARTCODE:

  355.             return state;

  356.         }

  357.     }

  358. 

  359.     return 0;

  360. }

  361. 

  362. /**

  363.  * find the given startcode.

  364.  * @param code the startcode

  365.  * @param pos the start position of the search, or -1 if the current position

  366.  * @returns the position of the startcode or -1 if not found

  367.  */

  368. static int64_t find_startcode(ByteIOContext *bc, uint64_t code, int64_t pos){

  369.     for(;;){

  370.         uint64_t startcode= find_any_startcode(bc, pos);

  371.         if(startcode == code)

  372.             return url_ftell(bc) - 8;

  373.         else if(startcode == 0)

  374.             return -1;

  375.         pos=-1;

  376.     }

  377. }

  378. 

  379. #ifdef CONFIG_ENCODERS

  380. static void put_v(ByteIOContext *bc, uint64_t val)

  381. {

  382.     int i;

  383. 

  384.     val &= 0x7FFFFFFFFFFFFFFFULL; // FIXME can only encode upto 63 bits currently

  385.     i= get_length(val);

  386. 

  387.     for (i-=7; i>0; i-=7){

  388. 	put_byte(bc, 0x80 | (val>>i));

  389.     }

  390. 

  391.     put_byte(bc, val&0x7f);

  392. }

  393. 

  394. /**

  395.  * stores a string as vb.

  396.  */

  397. static void put_str(ByteIOContext *bc, const char *string){

  398.     int len= strlen(string);

  399.     

  400.     put_v(bc, len);

  401.     put_buffer(bc, string, len);

  402. }

  403. 

  404. static void put_vb(ByteIOContext *bc, uint64_t val){

  405.     int i;

  406.     

  407.     for (i=8; val>>i; i+=8);

  408. 

  409.     put_v(bc, i>>3);

  410.     for(i-=8; i>=0; i-=8)

  411.         put_byte(bc, (val>>i)&0xFF);

  412. }

  413. 

  414. static int put_packetheader(NUTContext *nut, ByteIOContext *bc, int max_size, int calculate_checksum)

  415. {

  416.     put_flush_packet(bc);

  417.     nut->last_packet_start= nut->packet_start;

  418.     nut->packet_start+= nut->written_packet_size;

  419.     nut->packet_size_pos = url_ftell(bc);

  420.     nut->written_packet_size = max_size;

  421.     

  422.     if(calculate_checksum)

  423.         init_checksum(bc, update_adler32, 0);

  424. 

  425.     /* packet header */

  426.     put_v(bc, nut->written_packet_size); /* forward ptr */

  427.     put_v(bc, nut->packet_start - nut->last_packet_start); /* backward ptr */

  428. 

  429.     return 0;

  430. }

  431. 

  432. static int update_packetheader(NUTContext *nut, ByteIOContext *bc, int additional_size, int calculate_checksum){

  433.     int64_t start= nut->packet_start;

  434.     int64_t cur= url_ftell(bc);

  435.     int size= cur - start + additional_size;

  436.     

  437.     if(calculate_checksum)

  438.         size += 4;

  439.     

  440.     if(size != nut->written_packet_size){

  441.         int i;

  442. 

  443.         assert( size <= nut->written_packet_size );

  444.     

  445.         url_fseek(bc, nut->packet_size_pos, SEEK_SET);

  446.         for(i=get_length(size); i < get_length(nut->written_packet_size); i+=7)

  447.             put_byte(bc, 0x80);

  448.         put_v(bc, size);

  449. 

  450.         url_fseek(bc, cur, SEEK_SET);

  451.         nut->written_packet_size= size; //FIXME may fail if multiple updates with differing sizes, as get_length may differ

  452.         

  453.         if(calculate_checksum)

  454.             put_be32(bc, get_checksum(bc));

  455.     }

  456.     

  457.     return 0;

  458. }

  459. 

  460. static int nut_write_header(AVFormatContext *s)

  461. {

  462.     NUTContext *nut = s->priv_data;

  463.     ByteIOContext *bc = &s->pb;

  464.     AVCodecContext *codec;

  465.     int i, j;

  466. 

  467.     nut->avf= s;

  468.     

  469.     nut->stream =	

  470. 	av_mallocz(sizeof(StreamContext)*s->nb_streams);

  471.     

  472.     av_set_pts_info(s, 60, 1, AV_TIME_BASE);

  473.     

  474.     /* main header */

  475.     put_be64(bc, MAIN_STARTCODE);

  476.     put_packetheader(nut, bc, 120+5*256, 1);

  477.     put_v(bc, 1); /* version */

  478.     put_v(bc, s->nb_streams);

  479.     

  480.     build_frame_code(s);

  481.     assert(nut->frame_code['N'].flags == 1);

  482.     for(i=0; i<256;){

  483.         int tmp_flags = nut->frame_code[i].flags;

  484.         int tmp_stream= nut->frame_code[i].stream_id_plus1;

  485.         int tmp_mul   = nut->frame_code[i].size_mul;

  486.         int tmp_size  = nut->frame_code[i].size_lsb;

  487.         put_v(bc, tmp_flags);

  488.         put_v(bc, tmp_stream);

  489.         put_v(bc, tmp_mul);

  490.         put_v(bc, tmp_size);

  491. 

  492.         for(j=0; i<256; j++,i++){

  493.             if(nut->frame_code[i].flags           != tmp_flags ) break;

  494.             if(nut->frame_code[i].stream_id_plus1 != tmp_stream) break;

  495.             if(nut->frame_code[i].size_mul        != tmp_mul   ) break;

  496.             if(nut->frame_code[i].size_lsb        != tmp_size  ) break;

  497.             if(++tmp_size >= tmp_mul){

  498.                 tmp_size=0;

  499.                 tmp_stream++;

  500.             }

  501.         }

  502.         put_v(bc, j);

  503.     }

  504. 

  505.     update_packetheader(nut, bc, 0, 1);

  506.     

  507.     /* stream headers */

  508.     for (i = 0; i < s->nb_streams; i++)

  509.     {

  510. 	int nom, denom, gcd;

  511. 

  512. 	codec = &s->streams[i]->codec;

  513. 	

  514. 	put_be64(bc, STREAM_STARTCODE);

  515. 	put_packetheader(nut, bc, 120 + codec->extradata_size, 1);

  516. 	put_v(bc, i /*s->streams[i]->index*/);

  517. 	put_v(bc, (codec->codec_type == CODEC_TYPE_AUDIO) ? 32 : 0);

  518. 	if (codec->codec_tag)

  519. 	    put_vb(bc, codec->codec_tag);

  520. 	else if (codec->codec_type == CODEC_TYPE_VIDEO)

  521. 	{

  522. 	    put_vb(bc, codec_get_bmp_tag(codec->codec_id));

  523. 	}

  524. 	else if (codec->codec_type == CODEC_TYPE_AUDIO)

  525. 	{

  526. 	    put_vb(bc, codec_get_wav_tag(codec->codec_id));

  527. 	}

  528.         else

  529.             put_vb(bc, 0);

  530. 

  531. 	if (codec->codec_type == CODEC_TYPE_VIDEO)

  532. 	{

  533. 	    nom = codec->frame_rate;

  534. 	    denom = codec->frame_rate_base;

  535. 	}

  536. 	else

  537. 	{

  538. 	    nom = codec->sample_rate;

  539.             if(codec->frame_size>0)

  540.                 denom= codec->frame_size;

  541.             else

  542.                 denom= 1; //unlucky

  543. 	}

  544.         gcd= ff_gcd(nom, denom);

  545.         nom   /= gcd;

  546.         denom /= gcd;

  547.         nut->stream[i].rate_num= nom;

  548.         nut->stream[i].rate_den= denom;

  549. 

  550. 	put_v(bc, codec->bit_rate);

  551. 	put_vb(bc, 0); /* no language code */

  552. 	put_v(bc, nom);

  553. 	put_v(bc, denom);

  554.         if(nom / denom < 1000)

  555. 	    nut->stream[i].msb_timestamp_shift = 7;

  556.         else

  557. 	    nut->stream[i].msb_timestamp_shift = 14;

  558. 	put_v(bc, nut->stream[i].msb_timestamp_shift);

  559. 	for(j=0; j<3; j++)

  560. 		put_v(bc, nut->stream[i].initial_pts_predictor[j]);

  561. 	for(j=0; j<2; j++)

  562. 		put_v(bc, nut->stream[i].initial_size_predictor[j]);

  563. 	put_byte(bc, 0); /* flags: 0x1 - fixed_fps, 0x2 - index_present */

  564. 	

  565.         if(codec->extradata_size){

  566.             put_v(bc, 1);

  567.             put_v(bc, codec->extradata_size);

  568.             put_buffer(bc, codec->extradata, codec->extradata_size);            

  569.         }

  570. 	put_v(bc, 0); /* end of codec specific headers */

  571. 	

  572. 	switch(codec->codec_type)

  573. 	{

  574. 	    case CODEC_TYPE_AUDIO:

  575. 		put_v(bc, (codec->sample_rate * denom) / nom);

  576. 		put_v(bc, codec->channels);

  577. 		break;

  578. 	    case CODEC_TYPE_VIDEO:

  579. 		put_v(bc, codec->width);

  580. 		put_v(bc, codec->height);

  581. 		put_v(bc, codec->sample_aspect_ratio.num);

  582. 		put_v(bc, codec->sample_aspect_ratio.den);

  583. 		put_v(bc, 0); /* csp type -- unknown */

  584. 		break;

  585.             default:

  586.                 break;

  587. 	}

  588.         update_packetheader(nut, bc, 0, 1);

  589.     }

  590. 

  591.     /* info header */

  592.     put_be64(bc, INFO_STARTCODE);

  593.     put_packetheader(nut, bc, 30+strlen(s->author)+strlen(s->title)+

  594.         strlen(s->comment)+strlen(s->copyright)+strlen(LIBAVFORMAT_IDENT), 1); 

  595.     if (s->author[0])

  596.     {

  597.         put_v(bc, 9); /* type */

  598.         put_str(bc, s->author);

  599.     }

  600.     if (s->title[0])

  601.     {

  602.         put_v(bc, 10); /* type */

  603.         put_str(bc, s->title);

  604.     }

  605.     if (s->comment[0])

  606.     {

  607.         put_v(bc, 11); /* type */

  608.         put_str(bc, s->comment);

  609.     }

  610.     if (s->copyright[0])

  611.     {

  612.         put_v(bc, 12); /* type */

  613.         put_str(bc, s->copyright);

  614.     }

  615.     /* encoder */

  616.     put_v(bc, 13); /* type */

  617.     put_str(bc, LIBAVFORMAT_IDENT);

  618.     

  619.     put_v(bc, 0); /* eof info */

  620.     update_packetheader(nut, bc, 0, 1);

  621.         

  622.     put_flush_packet(bc);

  623.     

  624.     return 0;

  625. }

  626. 

  627. static int nut_write_packet(AVFormatContext *s, int stream_index, 

  628. 			    const uint8_t *buf, int size, int64_t pts)

  629. {

  630.     NUTContext *nut = s->priv_data;

  631.     StreamContext *stream= &nut->stream[stream_index];

  632.     ByteIOContext *bc = &s->pb;

  633.     int key_frame = 0, full_pts=0;

  634.     AVCodecContext *enc;

  635.     int64_t lsb_pts, delta_pts;

  636.     int frame_type, best_length, frame_code, flags, i, size_mul, size_lsb;

  637.     const int64_t frame_start= url_ftell(bc);

  638. 

  639.     if (stream_index > s->nb_streams)

  640. 	return 1;

  641.         

  642.     pts= (av_rescale(pts, stream->rate_num, stream->rate_den) + AV_TIME_BASE/2) / AV_TIME_BASE;

  643. 

  644.     enc = &s->streams[stream_index]->codec;

  645.     key_frame = enc->coded_frame->key_frame;

  646.     delta_pts= pts - stream->last_pts;

  647.     

  648.     frame_type=0;

  649.     if(frame_start + size + 20 - FFMAX(nut->last_frame_start[1], nut->last_frame_start[2]) > MAX_TYPE1_DISTANCE)

  650.         frame_type=1;

  651.     if(key_frame){

  652.         if(frame_type==1 && frame_start + size - nut->last_frame_start[2] > MAX_TYPE2_DISTANCE)

  653.             frame_type=2;

  654.         if(!stream->last_key_frame)

  655.             frame_type=2;

  656.     }

  657. 

  658.     if(frame_type>0){

  659.         update_packetheader(nut, bc, 0, 0);

  660.         reset(s);

  661.         full_pts=1;

  662.     }

  663.     //FIXME ensure that the timestamp can be represented by either delta or lsb or full_pts=1

  664. 

  665.     lsb_pts = pts & ((1 << stream->msb_timestamp_shift)-1);

  666. 

  667.     best_length=INT_MAX;

  668.     frame_code= -1;

  669.     for(i=0; i<256; i++){

  670.         int stream_id_plus1= nut->frame_code[i].stream_id_plus1;

  671.         int fc_key_frame;

  672.         int length=0;

  673.         size_mul= nut->frame_code[i].size_mul;

  674.         size_lsb= nut->frame_code[i].size_lsb;

  675.         flags= nut->frame_code[i].flags;

  676. 

  677.         if(stream_id_plus1 == 0) length+= get_length(stream_index);

  678.         else if(stream_id_plus1 - 1 != stream_index)

  679.             continue;

  680.         fc_key_frame= !!(flags & FLAG_KEY_FRAME);

  681. 

  682.         assert(key_frame==0 || key_frame==1);

  683.         if(fc_key_frame != key_frame)

  684.             continue;

  685. 

  686.         if((!!(flags & FLAG_FRAME_TYPE)) != (frame_type > 0))

  687.             continue;

  688.         

  689.         if(size_mul <= size_lsb){

  690.             int p= stream->lru_size[size_lsb - size_mul];

  691.             if(p != size)

  692.                 continue;

  693.         }else{

  694.             if(size % size_mul != size_lsb)

  695.                 continue;

  696.             if(flags & FLAG_DATA_SIZE)

  697.                 length += get_length(size / size_mul);

  698.             else if(size/size_mul)

  699.                 continue;

  700.         }

  701. 

  702.         if(full_pts != ((flags & FLAG_PTS) && (flags & FLAG_FULL_PTS)))

  703.             continue;

  704.             

  705.         if(flags&FLAG_PTS){

  706.             if(flags&FLAG_FULL_PTS){

  707.                 length += get_length(pts);

  708.             }else{

  709.                 length += get_length(lsb_pts);

  710.             }

  711.         }else{

  712.             int delta= stream->lru_pts_delta[(flags & 12)>>2];

  713.             if(delta != pts - stream->last_pts)

  714.                 continue;

  715.             assert(frame_type == 0);

  716.         }

  717. 

  718.         if(length < best_length){

  719.             best_length= length;

  720.             frame_code=i;

  721.         }

  722. //    av_log(s, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d %d %d\n", key_frame, frame_type, full_pts, size, stream_index, flags, size_mul, size_lsb, stream_id_plus1, length);

  723.     }

  724. 

  725.     assert(frame_code != -1);

  726.     flags= nut->frame_code[frame_code].flags;

  727.     size_mul= nut->frame_code[frame_code].size_mul;

  728.     size_lsb= nut->frame_code[frame_code].size_lsb;

  729. #if 0

  730.     best_length /= 7;

  731.     best_length ++; //frame_code

  732.     if(frame_type>0){

  733.         best_length += 4; //packet header

  734.         if(frame_type>1)

  735.             best_length += 8; // startcode

  736.     }

  737.     av_log(s, AV_LOG_DEBUG, "kf:%d ft:%d pt:%d fc:%2X len:%2d size:%d stream:%d flag:%d mul:%d lsb:%d s+1:%d pts_delta:%d\n", key_frame, frame_type, full_pts ? 2 : ((flags & FLAG_PTS) ? 1 : 0), frame_code, best_length, size, stream_index, flags, size_mul, size_lsb, nut->frame_code[frame_code].stream_id_plus1,(int)(pts - stream->last_pts));

  738. #endif

  739. 

  740.     if (frame_type==2)

  741. 	put_be64(bc, KEYFRAME_STARTCODE);

  742.     put_byte(bc, frame_code);

  743. 

  744.     if(frame_type>0)

  745.         put_packetheader(nut, bc, FFMAX(size+20, MAX_TYPE1_DISTANCE), 0);

  746.     if(nut->frame_code[frame_code].stream_id_plus1 == 0)

  747.         put_v(bc, stream_index);

  748.     if (flags & FLAG_PTS){

  749.         if (flags & FLAG_FULL_PTS)

  750.             put_v(bc, pts);

  751.         else

  752.             put_v(bc, lsb_pts);

  753.     }

  754.     if(flags & FLAG_DATA_SIZE)

  755.         put_v(bc, size / size_mul);

  756.     if(size > MAX_TYPE1_DISTANCE){

  757.         assert(frame_type > 0);

  758.         update_packetheader(nut, bc, size, 0);

  759.     }

  760.     

  761.     put_buffer(bc, buf, size);

  762. 

  763.     update(nut, stream_index, frame_start, frame_type, frame_code, key_frame, size, pts);

  764.     

  765.     return 0;

  766. }

  767. 

  768. static int nut_write_trailer(AVFormatContext *s)

  769. {

  770.     NUTContext *nut = s->priv_data;

  771.     ByteIOContext *bc = &s->pb;

  772. 

  773.     update_packetheader(nut, bc, 0, 0);

  774. 

  775. #if 0

  776.     int i;

  777. 

  778.     /* WRITE INDEX */

  779. 

  780.     for (i = 0; s->nb_streams; i++)

  781.     {

  782. 	put_be64(bc, INDEX_STARTCODE);

  783. 	put_packetheader(nut, bc, 64, 1);

  784. 	put_v(bc, s->streams[i]->id);

  785. 	put_v(bc, ...);

  786.         update_packetheader(nut, bc, 0, 1);

  787.     }

  788. #endif

  789. 

  790.     put_flush_packet(bc);

  791.     

  792.     av_freep(&nut->stream);

  793. 

  794.     return 0;

  795. }

  796. #endif //CONFIG_ENCODERS

  797. 

  798. static int nut_probe(AVProbeData *p)

  799. {

  800.     int i;

  801.     uint64_t code;

  802. 

  803.     code = 0xff;

  804.     for (i = 0; i < p->buf_size; i++) {

  805.         int c = p->buf[i];

  806.         code = (code << 8) | c;

  807.         if (code == MAIN_STARTCODE)

  808.             return AVPROBE_SCORE_MAX;

  809.     }

  810.     return 0;

  811. }

  812. 

  813. static int decode_main_header(NUTContext *nut){

  814.     AVFormatContext *s= nut->avf;

  815.     ByteIOContext *bc = &s->pb;

  816.     uint64_t tmp;

  817.     int i, j;

  818.     

  819.     get_packetheader(nut, bc, 8, 1);

  820. 

  821.     tmp = get_v(bc);

  822.     if (tmp != 1){

  823. 	av_log(s, AV_LOG_ERROR, "bad version (%Ld)\n", tmp);

  824.         return -1;

  825.     }

  826.     

  827.     nut->stream_count = get_v(bc);

  828. 

  829.     for(i=0; i<256;){

  830.         int tmp_flags = get_v(bc);

  831.         int tmp_stream= get_v(bc);

  832.         int tmp_mul   = get_v(bc);

  833.         int tmp_size  = get_v(bc);

  834.         int count     = get_v(bc);

  835. 

  836.         if(count == 0 || i+count > 256){

  837.             av_log(s, AV_LOG_ERROR, "illegal count %d at %d\n", count, i);

  838.             return -1;

  839.         }

  840. 

  841.         if((tmp_flags & FLAG_FRAME_TYPE) && tmp_flags != 1){

  842.             if(!(tmp_flags & FLAG_PTS) || !(tmp_flags & FLAG_FULL_PTS) ){

  843.                 av_log(s, AV_LOG_ERROR, "no full pts in non 0 frame type\n");

  844.                 return -1;

  845.             }

  846.         }

  847. 

  848.         for(j=0; j<count; j++,i++){

  849.             if(tmp_stream > nut->stream_count + 1){

  850.                 av_log(s, AV_LOG_ERROR, "illegal stream number\n");

  851.                 return -1;

  852.             }

  853. 

  854.             nut->frame_code[i].flags           = tmp_flags ;

  855.             nut->frame_code[i].stream_id_plus1 = tmp_stream;

  856.             nut->frame_code[i].size_mul        = tmp_mul   ;

  857.             nut->frame_code[i].size_lsb        = tmp_size  ;

  858.             if(++tmp_size >= tmp_mul){

  859.                 tmp_size=0;

  860.                 tmp_stream++;

  861.             }

  862.         }

  863.     }

  864.     if(nut->frame_code['N'].flags != 1){

  865.         av_log(s, AV_LOG_ERROR, "illegal frame_code table\n");

  866.         return -1;

  867.     }

  868. 

  869.     if(check_checksum(bc)){

  870.         av_log(s, AV_LOG_ERROR, "Main header checksum missmatch\n");

  871.         return -1;

  872.     }

  873. 

  874.     return 0;

  875. }

  876. 

  877. static int decode_stream_header(NUTContext *nut){

  878.     AVFormatContext *s= nut->avf;

  879.     ByteIOContext *bc = &s->pb;

  880.     int class, nom, denom, stream_id, i;

  881.     uint64_t tmp;

  882.     AVStream *st;

  883.     

  884.     get_packetheader(nut, bc, 8, 1);

  885.     stream_id= get_v(bc);

  886.     if(stream_id >= nut->stream_count || s->streams[stream_id])

  887.         return -1;

  888.     

  889.     st = av_new_stream(s, stream_id);

  890.     if (!st)

  891.         return AVERROR_NOMEM;

  892.     class = get_v(bc);

  893.     tmp = get_vb(bc);

  894.     st->codec.codec_tag= tmp;

  895.     switch(class)

  896.     {

  897.         case 0:

  898.             st->codec.codec_type = CODEC_TYPE_VIDEO;

  899.             st->codec.codec_id = codec_get_bmp_id(tmp);

  900.             if (st->codec.codec_id == CODEC_ID_NONE)

  901.                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");

  902.             break;

  903.         case 32:

  904.             st->codec.codec_type = CODEC_TYPE_AUDIO;

  905.             st->codec.codec_id = codec_get_wav_id(tmp);

  906.             if (st->codec.codec_id == CODEC_ID_NONE)

  907.                 av_log(s, AV_LOG_ERROR, "Unknown codec?!\n");

  908.             break;

  909.         default:

  910.             av_log(s, AV_LOG_ERROR, "Unknown stream class (%d)\n", class);

  911.             return -1;

  912.     }

  913.     s->bit_rate += get_v(bc);

  914.     get_vb(bc); /* language code */

  915.     nom = get_v(bc);

  916.     denom = get_v(bc);

  917.     nut->stream[stream_id].msb_timestamp_shift = get_v(bc);

  918.     for(i=0; i<3; i++)

  919.             nut->stream[stream_id].initial_pts_predictor[i]= get_v(bc);

  920.     for(i=0; i<2; i++)

  921.             nut->stream[stream_id].initial_size_predictor[i]= get_v(bc);

  922.     get_byte(bc); /* flags */

  923. 

  924.     /* codec specific data headers */

  925.     while(get_v(bc) != 0){

  926.         st->codec.extradata_size= get_v(bc);

  927.         st->codec.extradata= av_mallocz(st->codec.extradata_size);

  928.         get_buffer(bc, st->codec.extradata, st->codec.extradata_size);            

  929. //	    url_fskip(bc, get_v(bc));

  930.     }

  931.     

  932.     if (class == 0) /* VIDEO */

  933.     {

  934.         st->codec.width = get_v(bc);

  935.         st->codec.height = get_v(bc);

  936.         st->codec.sample_aspect_ratio.num= get_v(bc);

  937.         st->codec.sample_aspect_ratio.den= get_v(bc);

  938.         get_v(bc); /* csp type */

  939. 

  940.         st->codec.frame_rate = nom;

  941.         st->codec.frame_rate_base = denom;

  942.     }

  943.     if (class == 32) /* AUDIO */

  944.     {

  945.         st->codec.sample_rate = (get_v(bc) * nom) / denom;

  946.         st->codec.channels = get_v(bc);

  947.     }

  948.     if(check_checksum(bc)){

  949.         av_log(s, AV_LOG_ERROR, "Stream header %d checksum missmatch\n", stream_id);

  950.         return -1;

  951.     }

  952.     nut->stream[stream_id].rate_num= nom;

  953.     nut->stream[stream_id].rate_den= denom;

  954.     return 0;

  955. }

  956. 

  957. static int decode_info_header(NUTContext *nut){

  958.     AVFormatContext *s= nut->avf;

  959.     ByteIOContext *bc = &s->pb;

  960.     

  961.     get_packetheader(nut, bc, 8, 1);

  962. 

  963.     for(;;){

  964.         int id= get_v(bc);

  965.         char *name, *type, custom_name[256], custom_type[256];

  966. 

  967.         if(!id)

  968.             break;

  969.         else if(id >= sizeof(info_table)/sizeof(info_table[0])){

  970.             av_log(s, AV_LOG_ERROR, "info id is too large %d %d\n", id, sizeof(info_table)/sizeof(info_table[0]));

  971.             return -1;

  972.         }

  973. 

  974.         type= info_table[id][1];

  975.         name= info_table[id][0];

  976. //av_log(s, AV_LOG_DEBUG, "%d %s %s\n", id, type, name);

  977. 

  978.         if(!type){

  979.             get_str(bc, custom_type, sizeof(custom_type));

  980.             type= custom_type;

  981.         }

  982.         if(!name){

  983.             get_str(bc, custom_name, sizeof(custom_name));

  984.             name= custom_name;

  985.         }

  986.         

  987.         if(!strcmp(type, "v")){

  988.             int value= get_v(bc);

  989.         }else{

  990.             if(!strcmp(name, "Author"))

  991.                 get_str(bc, s->author, sizeof(s->author));

  992.             else if(!strcmp(name, "Title"))

  993.                 get_str(bc, s->title, sizeof(s->title));

  994.             else if(!strcmp(name, "Copyright"))

  995.                 get_str(bc, s->copyright, sizeof(s->copyright));

  996.             else if(!strcmp(name, "Description"))

  997.                 get_str(bc, s->comment, sizeof(s->comment));

  998.             else

  999.                 get_str(bc, NULL, 0);

  1000.         }

  1001.     }

  1002.     if(check_checksum(bc)){

  1003.         av_log(s, AV_LOG_ERROR, "Info header checksum missmatch\n");

  1004.         return -1;

  1005.     }

  1006.     return 0;

  1007. }

  1008. 

  1009. static int nut_read_header(AVFormatContext *s, AVFormatParameters *ap)

  1010. {

  1011.     NUTContext *nut = s->priv_data;

  1012.     ByteIOContext *bc = &s->pb;

  1013.     int64_t pos;

  1014.     int inited_stream_count;

  1015. 

  1016.     nut->avf= s;

  1017.     

  1018.     av_set_pts_info(s, 60, 1, AV_TIME_BASE);

  1019. 

  1020.     /* main header */

  1021.     pos=0;

  1022.     for(;;){

  1023.         pos= find_startcode(bc, MAIN_STARTCODE, pos)+1;

  1024.         if (pos<0){

  1025.             av_log(s, AV_LOG_ERROR, "no main startcode found\n");

  1026.             return -1;

  1027.         }

  1028.         if(decode_main_header(nut) >= 0)

  1029.             break;

  1030.     }

  1031.     

  1032.     

  1033.     s->bit_rate = 0;

  1034. 

  1035.     nut->stream = av_malloc(sizeof(StreamContext)*nut->stream_count);

  1036. 

  1037.     /* stream headers */

  1038.     pos=0;

  1039.     for(inited_stream_count=0; inited_stream_count < nut->stream_count;){

  1040.         pos= find_startcode(bc, STREAM_STARTCODE, pos)+1;

  1041.         if (pos<0){

  1042.             av_log(s, AV_LOG_ERROR, "not all stream headers found\n");

  1043.             return -1;

  1044.         }

  1045.         if(decode_stream_header(nut) >= 0)

  1046.             inited_stream_count++;

  1047.     }

  1048. 

  1049.     /* info headers */

  1050.     pos=0;

  1051.     for(;;){

  1052.         uint64_t startcode= find_any_startcode(bc, pos);

  1053.         pos= url_ftell(bc);

  1054. 

  1055.         if(startcode==0){

  1056.             av_log(s, AV_LOG_ERROR, "EOF before video frames\n");

  1057.             return -1;

  1058.         }else if(startcode == KEYFRAME_STARTCODE){

  1059.             nut->next_startcode= startcode;

  1060.             break;

  1061.         }else if(startcode != INFO_STARTCODE){

  1062.             continue;

  1063.         }

  1064. 

  1065.         decode_info_header(nut);

  1066.     }

  1067. 

  1068.     return 0;

  1069. }

  1070. 

  1071. static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code, int frame_type){

  1072.     AVFormatContext *s= nut->avf;

  1073.     StreamContext *stream;

  1074.     ByteIOContext *bc = &s->pb;

  1075.     int size, flags, size_mul, size_lsb, stream_id;

  1076.     int key_frame = 0;

  1077.     int64_t pts = 0;

  1078.     const int prefix_len= frame_type == 2 ? 8+1 : 1;

  1079.     const int64_t frame_start= url_ftell(bc) - prefix_len;

  1080. 

  1081.     flags= nut->frame_code[frame_code].flags;

  1082.     size_mul= nut->frame_code[frame_code].size_mul;

  1083.     size_lsb= nut->frame_code[frame_code].size_lsb;

  1084.     stream_id= nut->frame_code[frame_code].stream_id_plus1 - 1;

  1085. 

  1086.     if(flags & FLAG_FRAME_TYPE){

  1087.         reset(s);

  1088.         if(get_packetheader(nut, bc, prefix_len, 0) < 0)

  1089.             return -1;

  1090.         if(frame_type!=2)

  1091.             frame_type= 1;

  1092.     }

  1093. 

  1094.     if(stream_id==-1)

  1095.         stream_id= get_v(bc);

  1096.     if(stream_id >= s->nb_streams){

  1097.         av_log(s, AV_LOG_ERROR, "illegal stream_id\n");

  1098.         return -1;

  1099.     }

  1100.     stream= &nut->stream[stream_id];

  1101. 

  1102. //    av_log(s, AV_LOG_DEBUG, "ft:%d ppts:%d %d %d\n", frame_type, stream->lru_pts_delta[0], stream->lru_pts_delta[1], stream->lru_pts_delta[2]);

  1103.     

  1104.     key_frame= !!(flags & FLAG_KEY_FRAME);

  1105. 

  1106.     if(flags & FLAG_PTS){

  1107.         if(flags & FLAG_FULL_PTS){

  1108.             pts= get_v(bc);

  1109.             if(frame_type && key_frame){

  1110.                 int64_t av_pts= pts * AV_TIME_BASE * stream->rate_den / stream->rate_num;

  1111.                 av_add_index_entry(

  1112.                     s->streams[stream_id], 

  1113.                     frame_start, 

  1114.                     av_pts, 

  1115.                     frame_start - nut->stream[stream_id].last_sync_pos,

  1116.                     AVINDEX_KEYFRAME);

  1117.                 nut->stream[stream_id].last_sync_pos= frame_start;

  1118.                 assert(nut->packet_start == frame_start);

  1119.             }

  1120.         }else{

  1121.             int64_t mask = (1<<stream->msb_timestamp_shift)-1;

  1122.             int64_t delta= stream->last_pts - mask/2;

  1123.             pts= ((get_v(bc) - delta)&mask) + delta;

  1124.         }

  1125.     }else{

  1126.         pts= stream->last_pts + stream->lru_pts_delta[(flags&12)>>2];

  1127.     }

  1128.   

  1129.     if(size_mul <= size_lsb){

  1130.         size= stream->lru_size[size_lsb - size_mul];

  1131.     }else{

  1132.         if(flags & FLAG_DATA_SIZE)

  1133.             size= size_mul*get_v(bc) + size_lsb;

  1134.         else

  1135.             size= size_lsb;

  1136.     }

  1137.       

  1138. //av_log(s, AV_LOG_DEBUG, "fs:%lld fc:%d ft:%d kf:%d pts:%lld size:%d\n", frame_start, frame_code, frame_type, key_frame, pts, size);

  1139. 

  1140.     if(url_ftell(bc) - nut->packet_start + size > nut->written_packet_size){

  1141.         av_log(s, AV_LOG_ERROR, "frame size too large\n");

  1142.         return -1;

  1143.     }

  1144.     

  1145.     av_new_packet(pkt, size);

  1146.     get_buffer(bc, pkt->data, size);

  1147.     pkt->stream_index = stream_id;

  1148.     if (key_frame)

  1149. 	pkt->flags |= PKT_FLAG_KEY;

  1150.     pkt->pts = pts * AV_TIME_BASE * stream->rate_den / stream->rate_num;

  1151. 

  1152.     update(nut, stream_id, frame_start, frame_type, frame_code, key_frame, size, pts);

  1153.     

  1154.     return 0;

  1155. }

  1156. 

  1157. static int nut_read_packet(AVFormatContext *s, AVPacket *pkt)

  1158. {

  1159.     NUTContext *nut = s->priv_data;

  1160.     ByteIOContext *bc = &s->pb;

  1161.     int size, i, frame_code=0;

  1162.     int64_t pos;

  1163. 

  1164.     for(;;){

  1165.         int frame_type= 0;

  1166.         uint64_t tmp= nut->next_startcode;

  1167.         nut->next_startcode=0;

  1168. 

  1169.         if (url_feof(bc))

  1170.             return -1;

  1171. 

  1172.         if(!tmp){

  1173.             frame_code = get_byte(bc);

  1174.             if(frame_code == 'N'){

  1175.                 tmp= frame_code;

  1176.                 for(i=1; i<8; i++)

  1177.                     tmp = (tmp<<8) + get_byte(bc);

  1178.             }

  1179.         }

  1180.         switch(tmp){

  1181.         case MAIN_STARTCODE:

  1182.         case STREAM_STARTCODE:

  1183.         case INDEX_STARTCODE:

  1184.             get_packetheader(nut, bc, 8, 0);

  1185.             url_fseek(bc, nut->written_packet_size + nut->packet_start, SEEK_SET);

  1186.             break;

  1187.         case INFO_STARTCODE:

  1188.             if(decode_info_header(nut)<0)

  1189.                 goto resync;

  1190.             break;

  1191.         case KEYFRAME_STARTCODE:

  1192.             frame_type = 2;

  1193.             frame_code = get_byte(bc);

  1194.         case 0:

  1195.             if(decode_frame(nut, pkt, frame_code, frame_type)>=0)

  1196.                 return 0;

  1197.         default:

  1198. resync:

  1199. av_log(s, AV_LOG_DEBUG, "syncing from %lld\n", nut->packet_start+1);

  1200.             tmp= find_any_startcode(bc, nut->packet_start+1);

  1201.             if(tmp==0)

  1202.                 return -1;

  1203. av_log(s, AV_LOG_DEBUG, "sync\n");

  1204.             if(url_is_streamed(bc)){

  1205.                 nut->next_startcode= tmp;

  1206.                 break;

  1207.             }

  1208. 

  1209.             pos= url_ftell(bc) - 8;

  1210. av_log(s, AV_LOG_DEBUG, "at %lld code=%llX\n", pos, tmp);

  1211.             if(tmp==KEYFRAME_STARTCODE){

  1212.                 get_byte(bc);

  1213.             }

  1214.             get_v(bc);

  1215.             size= get_v(bc);

  1216.             

  1217.             while(size > 2 && size < 100000 && nut->packet_start < pos - size){

  1218.                 url_fseek(bc, pos - size, SEEK_SET);

  1219.                 frame_code= get_byte(bc);

  1220.                 if(!(nut->frame_code[ frame_code ].flags & FLAG_FRAME_TYPE))

  1221.                     break;

  1222.                 if(get_v(bc) != size)

  1223.                     break;

  1224.                 pos -= size;

  1225.                 size= get_v(bc);

  1226. av_log(s, AV_LOG_DEBUG, "steping back to %lld next %d\n", pos, size);

  1227.             }

  1228.             url_fseek(bc, pos, SEEK_SET);

  1229.             

  1230.             nut->written_packet_size= -1;

  1231.         }

  1232.     }

  1233. }

  1234. 

  1235. static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index, int64_t *pos_arg, int64_t pos_limit){

  1236.     NUTContext *nut = s->priv_data;

  1237.     StreamContext *stream;

  1238.     ByteIOContext *bc = &s->pb;

  1239.     int64_t pos, pts;

  1240.     uint64_t code;

  1241.     int frame_code,step, flags, stream_id, i;

  1242. av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%lld,%lld)\n", stream_index, *pos_arg, pos_limit);

  1243. 

  1244.     if(*pos_arg < 0)

  1245.         return AV_NOPTS_VALUE;

  1246. 

  1247.     // find a previous startcode, FIXME use forward search and follow backward pointers if undamaged stream

  1248.     pos= *pos_arg;

  1249.     step= FFMIN(16*1024, pos);

  1250.     do{

  1251.         pos-= step;

  1252.         code= find_any_startcode(bc, pos);

  1253. 

  1254.         if(code && url_ftell(bc) - 8 < *pos_arg)

  1255.             break;

  1256.         step= FFMIN(2*step, pos);

  1257.     }while(step);

  1258. 

  1259.     if(!code) //nothing found, not even after pos_arg

  1260.         return AV_NOPTS_VALUE;

  1261. 

  1262.     url_fseek(bc, -8, SEEK_CUR);

  1263.     for(i=0; i<s->nb_streams; i++)

  1264.         nut->stream[i].last_sync_pos= url_ftell(bc);

  1265.         

  1266.     for(;;){

  1267.         int64_t pos= url_ftell(bc);

  1268.         uint64_t tmp=0;

  1269.         int prefix_len=1;

  1270.         

  1271.         if(pos > pos_limit)

  1272.             return AV_NOPTS_VALUE;

  1273. 

  1274.         frame_code = get_byte(bc);

  1275.         if(frame_code == 'N'){

  1276.             tmp= frame_code;

  1277.             for(i=1; i<8; i++)

  1278.                 tmp = (tmp<<8) + get_byte(bc);

  1279.         }

  1280. //av_log(s, AV_LOG_DEBUG, "before switch %llX at=%lld\n", tmp, pos);

  1281. 

  1282.         switch(tmp){

  1283.         case MAIN_STARTCODE:

  1284.         case STREAM_STARTCODE:

  1285.         case INDEX_STARTCODE:

  1286.         case INFO_STARTCODE:

  1287.             nut->written_packet_size= -1;

  1288.             get_packetheader(nut, bc, 8, 0);

  1289.             url_fseek(bc, nut->written_packet_size + nut->packet_start, SEEK_SET);

  1290.             break;

  1291.         case KEYFRAME_STARTCODE:

  1292.             nut->written_packet_size= -1;

  1293.             prefix_len+=8;

  1294.             frame_code = get_byte(bc);

  1295.         case 0:

  1296.             flags= nut->frame_code[frame_code].flags;

  1297.             stream_id= nut->frame_code[frame_code].stream_id_plus1 - 1;

  1298. 

  1299.             if(get_packetheader(nut, bc, prefix_len, 0) < 0)

  1300.                 goto resync;

  1301. 

  1302.             if(!(flags & FLAG_FRAME_TYPE) || !(flags & FLAG_PTS) || !(flags & FLAG_FULL_PTS))

  1303.                 goto resync;

  1304. 

  1305.             if(stream_id==-1)

  1306.                 stream_id= get_v(bc);

  1307.             if(stream_id >= s->nb_streams)

  1308.                 goto resync;

  1309.                 

  1310.             stream= &nut->stream[stream_id];

  1311.             pts= get_v(bc) * AV_TIME_BASE * stream->rate_den / stream->rate_num;

  1312.     

  1313.             if(flags & FLAG_KEY_FRAME){

  1314.                 av_add_index_entry(

  1315.                     s->streams[stream_id], 

  1316.                     pos, 

  1317.                     pts, 

  1318.                     pos - nut->stream[stream_id].last_sync_pos,

  1319.                     AVINDEX_KEYFRAME);

  1320.                 nut->stream[stream_id].last_sync_pos= pos;

  1321.             }

  1322.             if(stream_id != stream_index || !(flags & FLAG_KEY_FRAME) || nut->packet_start < *pos_arg){

  1323.                 url_fseek(bc, nut->written_packet_size + nut->packet_start, SEEK_SET);

  1324.                 break;

  1325.             }

  1326.  

  1327.             *pos_arg= nut->packet_start;

  1328.             assert(nut->packet_start == pos);

  1329.             return pts;

  1330.         default:

  1331. resync:

  1332. av_log(s, AV_LOG_DEBUG, "syncing from %lld\n", nut->packet_start+1);

  1333.             if(!find_any_startcode(bc, nut->packet_start+1))

  1334.                 return AV_NOPTS_VALUE;

  1335. 

  1336.             url_fseek(bc, -8, SEEK_CUR);

  1337.         }

  1338.     }

  1339.     return AV_NOPTS_VALUE;

  1340. }

  1341. 

  1342. static int nut_read_seek(AVFormatContext *s, int stream_index, int64_t target_ts){

  1343.     NUTContext *nut = s->priv_data;

  1344.     int64_t pos;

  1345.     int i;

  1346. 

  1347.     if(av_seek_frame_binary(s, stream_index, target_ts) < 0)

  1348.         return -1;

  1349. 

  1350.     nut->written_packet_size= -1;

  1351.     pos= url_ftell(&s->pb);

  1352.     for(i=0; i<s->nb_streams; i++)

  1353.         nut->stream[i].last_sync_pos= pos;

  1354. 

  1355.     return 0;

  1356. }

  1357. 

  1358. static int nut_read_close(AVFormatContext *s)

  1359. {

  1360.     NUTContext *nut = s->priv_data;

  1361.     int i;

  1362. 

  1363.     for(i=0;i<s->nb_streams;i++) {

  1364.         av_freep(&s->streams[i]->codec.extradata);

  1365.     }

  1366.     av_freep(&nut->stream);

  1367. 

  1368.     return 0;

  1369. }

  1370. 

  1371. static AVInputFormat nut_iformat = {

  1372.     "nut",

  1373.     "nut format",

  1374.     sizeof(NUTContext),

  1375.     nut_probe,

  1376.     nut_read_header,

  1377.     nut_read_packet,

  1378.     nut_read_close,

  1379.     nut_read_seek,

  1380.     nut_read_timestamp,

  1381.     .extensions = "nut",

  1382. };

  1383. 

  1384. #ifdef CONFIG_ENCODERS

  1385. static AVOutputFormat nut_oformat = {

  1386.     "nut",

  1387.     "nut format",

  1388.     "video/x-nut",

  1389.     "nut",

  1390.     sizeof(NUTContext),

  1391. #ifdef CONFIG_VORBIS

  1392.     CODEC_ID_VORBIS,

  1393. #elif defined(CONFIG_MP3LAME)

  1394.     CODEC_ID_MP3,

  1395. #else

  1396.     CODEC_ID_MP2, /* AC3 needs liba52 decoder */

  1397. #endif

  1398.     CODEC_ID_MPEG4,

  1399.     nut_write_header,

  1400.     nut_write_packet,

  1401.     nut_write_trailer,

  1402. };

  1403. #endif //CONFIG_ENCODERS

  1404. 

  1405. int nut_init(void)

  1406. {

  1407.     av_register_input_format(&nut_iformat);

  1408. #ifdef CONFIG_ENCODERS

  1409.     av_register_output_format(&nut_oformat);

  1410. #endif //CONFIG_ENCODERS

  1411.     return 0;

  1412. }