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FFmpeg/libavformat/asfdec.c

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  1. /*

  2.  * ASF compatible demuxer

  3.  * Copyright (c) 2000, 2001 Fabrice Bellard

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

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

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

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. #include "libavutil/common.h"

  23. #include "libavcodec/mpegaudio.h"

  24. #include "avformat.h"

  25. #include "riff.h"

  26. #include "asf.h"

  27. #include "asfcrypt.h"

  28. 

  29. void ff_mms_set_stream_selection(URLContext *h, AVFormatContext *format);

  30. 

  31. #undef NDEBUG

  32. #include <assert.h>

  33. 

  34. #define FRAME_HEADER_SIZE 17

  35. // Fix Me! FRAME_HEADER_SIZE may be different.

  36. 

  37. static const ff_asf_guid index_guid = {

  38.     0x90, 0x08, 0x00, 0x33, 0xb1, 0xe5, 0xcf, 0x11, 0x89, 0xf4, 0x00, 0xa0, 0xc9, 0x03, 0x49, 0xcb

  39. };

  40. 

  41. static const ff_asf_guid stream_bitrate_guid = { /* (http://get.to/sdp) */

  42.     0xce, 0x75, 0xf8, 0x7b, 0x8d, 0x46, 0xd1, 0x11, 0x8d, 0x82, 0x00, 0x60, 0x97, 0xc9, 0xa2, 0xb2

  43. };

  44. /**********************************/

  45. /* decoding */

  46. 

  47. //#define DEBUG

  48. 

  49. #ifdef DEBUG

  50. #define PRINT_IF_GUID(g,cmp) \

  51. if (!guidcmp(g, &cmp)) \

  52.     dprintf(NULL, "(GUID: %s) ", #cmp)

  53. 

  54. static void print_guid(const ff_asf_guid *g)

  55. {

  56.     int i;

  57.     PRINT_IF_GUID(g, ff_asf_header);

  58.     else PRINT_IF_GUID(g, ff_asf_file_header);

  59.     else PRINT_IF_GUID(g, ff_asf_stream_header);

  60.     else PRINT_IF_GUID(g, ff_asf_audio_stream);

  61.     else PRINT_IF_GUID(g, ff_asf_audio_conceal_none);

  62.     else PRINT_IF_GUID(g, ff_asf_video_stream);

  63.     else PRINT_IF_GUID(g, ff_asf_video_conceal_none);

  64.     else PRINT_IF_GUID(g, ff_asf_command_stream);

  65.     else PRINT_IF_GUID(g, ff_asf_comment_header);

  66.     else PRINT_IF_GUID(g, ff_asf_codec_comment_header);

  67.     else PRINT_IF_GUID(g, ff_asf_codec_comment1_header);

  68.     else PRINT_IF_GUID(g, ff_asf_data_header);

  69.     else PRINT_IF_GUID(g, index_guid);

  70.     else PRINT_IF_GUID(g, ff_asf_head1_guid);

  71.     else PRINT_IF_GUID(g, ff_asf_head2_guid);

  72.     else PRINT_IF_GUID(g, ff_asf_my_guid);

  73.     else PRINT_IF_GUID(g, ff_asf_ext_stream_header);

  74.     else PRINT_IF_GUID(g, ff_asf_extended_content_header);

  75.     else PRINT_IF_GUID(g, ff_asf_ext_stream_embed_stream_header);

  76.     else PRINT_IF_GUID(g, ff_asf_ext_stream_audio_stream);

  77.     else PRINT_IF_GUID(g, ff_asf_metadata_header);

  78.     else PRINT_IF_GUID(g, stream_bitrate_guid);

  79.     else

  80.         dprintf(NULL, "(GUID: unknown) ");

  81.     for(i=0;i<16;i++)

  82.         dprintf(NULL, " 0x%02x,", (*g)[i]);

  83.     dprintf(NULL, "}\n");

  84. }

  85. #undef PRINT_IF_GUID

  86. #else

  87. #define print_guid(g)

  88. #endif

  89. 

  90. static int guidcmp(const void *g1, const void *g2)

  91. {

  92.     return memcmp(g1, g2, sizeof(ff_asf_guid));

  93. }

  94. 

  95. static void get_guid(ByteIOContext *s, ff_asf_guid *g)

  96. {

  97.     assert(sizeof(*g) == 16);

  98.     get_buffer(s, *g, sizeof(*g));

  99. }

  100. 

  101. #if 0

  102. static void get_str16(ByteIOContext *pb, char *buf, int buf_size)

  103. {

  104.     int len, c;

  105.     char *q;

  106. 

  107.     len = get_le16(pb);

  108.     q = buf;

  109.     while (len > 0) {

  110.         c = get_le16(pb);

  111.         if ((q - buf) < buf_size - 1)

  112.             *q++ = c;

  113.         len--;

  114.     }

  115.     *q = '\0';

  116. }

  117. #endif

  118. 

  119. static void get_str16_nolen(ByteIOContext *pb, int len, char *buf, int buf_size)

  120. {

  121.     char* q = buf;

  122.     len /= 2;

  123.     while (len--) {

  124.         uint8_t tmp;

  125.         PUT_UTF8(get_le16(pb), tmp, if (q - buf < buf_size - 1) *q++ = tmp;)

  126.     }

  127.     *q = '\0';

  128. }

  129. 

  130. static int asf_probe(AVProbeData *pd)

  131. {

  132.     /* check file header */

  133.     if (!guidcmp(pd->buf, &ff_asf_header))

  134.         return AVPROBE_SCORE_MAX;

  135.     else

  136.         return 0;

  137. }

  138. 

  139. static int get_value(ByteIOContext *pb, int type){

  140.     switch(type){

  141.         case 2: return get_le32(pb);

  142.         case 3: return get_le32(pb);

  143.         case 4: return get_le64(pb);

  144.         case 5: return get_le16(pb);

  145.         default:return INT_MIN;

  146.     }

  147. }

  148. 

  149. static void get_tag(AVFormatContext *s, const char *key, int type, int len)

  150. {

  151.     char value[1024];

  152.     if (type <= 1) {         // unicode or byte

  153.         get_str16_nolen(s->pb, len, value, sizeof(value));

  154.     } else if (type <= 5) {  // boolean or DWORD or QWORD or WORD

  155.         uint64_t num = get_value(s->pb, type);

  156.         snprintf(value, sizeof(value), "%"PRIu64, num);

  157.     } else {

  158.         url_fskip(s->pb, len);

  159.         return;

  160.     }

  161.     if (!strncmp(key, "WM/", 3))

  162.         key += 3;

  163.     av_metadata_set(&s->metadata, key, value);

  164. }

  165. 

  166. static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)

  167. {

  168.     ASFContext *asf = s->priv_data;

  169.     ff_asf_guid g;

  170.     ByteIOContext *pb = s->pb;

  171.     AVStream *st;

  172.     ASFStream *asf_st;

  173.     int size, i;

  174.     int64_t gsize;

  175.     AVRational dar[128];

  176.     uint32_t bitrate[128];

  177. 

  178.     memset(dar, 0, sizeof(dar));

  179.     memset(bitrate, 0, sizeof(bitrate));

  180. 

  181.     get_guid(pb, &g);

  182.     if (guidcmp(&g, &ff_asf_header))

  183.         return -1;

  184.     get_le64(pb);

  185.     get_le32(pb);

  186.     get_byte(pb);

  187.     get_byte(pb);

  188.     memset(&asf->asfid2avid, -1, sizeof(asf->asfid2avid));

  189.     for(;;) {

  190.         get_guid(pb, &g);

  191.         gsize = get_le64(pb);

  192.         dprintf(s, "%08"PRIx64": ", url_ftell(pb) - 24);

  193.         print_guid(&g);

  194.         dprintf(s, "  size=0x%"PRIx64"\n", gsize);

  195.         if (!guidcmp(&g, &ff_asf_data_header)) {

  196.             asf->data_object_offset = url_ftell(pb);

  197.             // if not streaming, gsize is not unlimited (how?), and there is enough space in the file..

  198.             if (!(asf->hdr.flags & 0x01) && gsize >= 100) {

  199.                 asf->data_object_size = gsize - 24;

  200.             } else {

  201.                 asf->data_object_size = (uint64_t)-1;

  202.             }

  203.             break;

  204.         }

  205.         if (gsize < 24)

  206.             return -1;

  207.         if (!guidcmp(&g, &ff_asf_file_header)) {

  208.             get_guid(pb, &asf->hdr.guid);

  209.             asf->hdr.file_size          = get_le64(pb);

  210.             asf->hdr.create_time        = get_le64(pb);

  211.             asf->nb_packets             = get_le64(pb);

  212.             asf->hdr.play_time          = get_le64(pb);

  213.             asf->hdr.send_time          = get_le64(pb);

  214.             asf->hdr.preroll            = get_le32(pb);

  215.             asf->hdr.ignore             = get_le32(pb);

  216.             asf->hdr.flags              = get_le32(pb);

  217.             asf->hdr.min_pktsize        = get_le32(pb);

  218.             asf->hdr.max_pktsize        = get_le32(pb);

  219.             asf->hdr.max_bitrate        = get_le32(pb);

  220.             asf->packet_size = asf->hdr.max_pktsize;

  221.         } else if (!guidcmp(&g, &ff_asf_stream_header)) {

  222.             enum CodecType type;

  223.             int type_specific_size, sizeX;

  224.             uint64_t total_size;

  225.             unsigned int tag1;

  226.             int64_t pos1, pos2, start_time;

  227.             int test_for_ext_stream_audio, is_dvr_ms_audio=0;

  228. 

  229.             pos1 = url_ftell(pb);

  230. 

  231.             st = av_new_stream(s, 0);

  232.             if (!st)

  233.                 return AVERROR(ENOMEM);

  234.             av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */

  235.             asf_st = av_mallocz(sizeof(ASFStream));

  236.             if (!asf_st)

  237.                 return AVERROR(ENOMEM);

  238.             st->priv_data = asf_st;

  239.             start_time = asf->hdr.preroll;

  240. 

  241.             if(!(asf->hdr.flags & 0x01)) { // if we aren't streaming...

  242.                 st->duration = asf->hdr.send_time /

  243.                     (10000000 / 1000) - start_time;

  244.             }

  245.             get_guid(pb, &g);

  246. 

  247.             test_for_ext_stream_audio = 0;

  248.             if (!guidcmp(&g, &ff_asf_audio_stream)) {

  249.                 type = CODEC_TYPE_AUDIO;

  250.             } else if (!guidcmp(&g, &ff_asf_video_stream)) {

  251.                 type = CODEC_TYPE_VIDEO;

  252.             } else if (!guidcmp(&g, &ff_asf_command_stream)) {

  253.                 type = CODEC_TYPE_DATA;

  254.             } else if (!guidcmp(&g, &ff_asf_ext_stream_embed_stream_header)) {

  255.                 test_for_ext_stream_audio = 1;

  256.                 type = CODEC_TYPE_UNKNOWN;

  257.             } else {

  258.                 return -1;

  259.             }

  260.             get_guid(pb, &g);

  261.             total_size = get_le64(pb);

  262.             type_specific_size = get_le32(pb);

  263.             get_le32(pb);

  264.             st->id = get_le16(pb) & 0x7f; /* stream id */

  265.             // mapping of asf ID to AV stream ID;

  266.             asf->asfid2avid[st->id] = s->nb_streams - 1;

  267. 

  268.             get_le32(pb);

  269. 

  270.             if (test_for_ext_stream_audio) {

  271.                 get_guid(pb, &g);

  272.                 if (!guidcmp(&g, &ff_asf_ext_stream_audio_stream)) {

  273.                     type = CODEC_TYPE_AUDIO;

  274.                     is_dvr_ms_audio=1;

  275.                     get_guid(pb, &g);

  276.                     get_le32(pb);

  277.                     get_le32(pb);

  278.                     get_le32(pb);

  279.                     get_guid(pb, &g);

  280.                     get_le32(pb);

  281.                 }

  282.             }

  283. 

  284.             st->codec->codec_type = type;

  285.             if (type == CODEC_TYPE_AUDIO) {

  286.                 get_wav_header(pb, st->codec, type_specific_size);

  287.                 if (is_dvr_ms_audio) {

  288.                     // codec_id and codec_tag are unreliable in dvr_ms

  289.                     // files. Set them later by probing stream.

  290.                     st->codec->codec_id = CODEC_ID_PROBE;

  291.                     st->codec->codec_tag = 0;

  292.                 }

  293.                 if (st->codec->codec_id == CODEC_ID_AAC) {

  294.                     st->need_parsing = AVSTREAM_PARSE_NONE;

  295.                 } else {

  296.                     st->need_parsing = AVSTREAM_PARSE_FULL;

  297.                 }

  298.                 /* We have to init the frame size at some point .... */

  299.                 pos2 = url_ftell(pb);

  300.                 if (gsize >= (pos2 + 8 - pos1 + 24)) {

  301.                     asf_st->ds_span = get_byte(pb);

  302.                     asf_st->ds_packet_size = get_le16(pb);

  303.                     asf_st->ds_chunk_size = get_le16(pb);

  304.                     get_le16(pb); //ds_data_size

  305.                     get_byte(pb); //ds_silence_data

  306.                 }

  307.                 //printf("Descrambling: ps:%d cs:%d ds:%d s:%d  sd:%d\n",

  308.                 //       asf_st->ds_packet_size, asf_st->ds_chunk_size,

  309.                 //       asf_st->ds_data_size, asf_st->ds_span, asf_st->ds_silence_data);

  310.                 if (asf_st->ds_span > 1) {

  311.                     if (!asf_st->ds_chunk_size

  312.                         || (asf_st->ds_packet_size/asf_st->ds_chunk_size <= 1)

  313.                         || asf_st->ds_packet_size % asf_st->ds_chunk_size)

  314.                         asf_st->ds_span = 0; // disable descrambling

  315.                 }

  316.                 switch (st->codec->codec_id) {

  317.                 case CODEC_ID_MP3:

  318.                     st->codec->frame_size = MPA_FRAME_SIZE;

  319.                     break;

  320.                 case CODEC_ID_PCM_S16LE:

  321.                 case CODEC_ID_PCM_S16BE:

  322.                 case CODEC_ID_PCM_U16LE:

  323.                 case CODEC_ID_PCM_U16BE:

  324.                 case CODEC_ID_PCM_S8:

  325.                 case CODEC_ID_PCM_U8:

  326.                 case CODEC_ID_PCM_ALAW:

  327.                 case CODEC_ID_PCM_MULAW:

  328.                     st->codec->frame_size = 1;

  329.                     break;

  330.                 default:

  331.                     /* This is probably wrong, but it prevents a crash later */

  332.                     st->codec->frame_size = 1;

  333.                     break;

  334.                 }

  335.             } else if (type == CODEC_TYPE_VIDEO) {

  336.                 get_le32(pb);

  337.                 get_le32(pb);

  338.                 get_byte(pb);

  339.                 size = get_le16(pb); /* size */

  340.                 sizeX= get_le32(pb); /* size */

  341.                 st->codec->width = get_le32(pb);

  342.                 st->codec->height = get_le32(pb);

  343.                 /* not available for asf */

  344.                 get_le16(pb); /* panes */

  345.                 st->codec->bits_per_coded_sample = get_le16(pb); /* depth */

  346.                 tag1 = get_le32(pb);

  347.                 url_fskip(pb, 20);

  348. //                av_log(s, AV_LOG_DEBUG, "size:%d tsize:%d sizeX:%d\n", size, total_size, sizeX);

  349.                 size= sizeX;

  350.                 if (size > 40) {

  351.                     st->codec->extradata_size = size - 40;

  352.                     st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

  353.                     get_buffer(pb, st->codec->extradata, st->codec->extradata_size);

  354.                 }

  355. 

  356.                 /* Extract palette from extradata if bpp <= 8 */

  357.                 /* This code assumes that extradata contains only palette */

  358.                 /* This is true for all paletted codecs implemented in ffmpeg */

  359.                 if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {

  360.                     st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));

  361. #ifdef WORDS_BIGENDIAN

  362.                     for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)

  363.                         st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);

  364. #else

  365.                     memcpy(st->codec->palctrl->palette, st->codec->extradata,

  366.                            FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));

  367. #endif

  368.                     st->codec->palctrl->palette_changed = 1;

  369.                 }

  370. 

  371.                 st->codec->codec_tag = tag1;

  372.                 st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);

  373.                 if(tag1 == MKTAG('D', 'V', 'R', ' '))

  374.                     st->need_parsing = AVSTREAM_PARSE_FULL;

  375.             }

  376.             pos2 = url_ftell(pb);

  377.             url_fskip(pb, gsize - (pos2 - pos1 + 24));

  378.         } else if (!guidcmp(&g, &ff_asf_comment_header)) {

  379.             int len1, len2, len3, len4, len5;

  380. 

  381.             len1 = get_le16(pb);

  382.             len2 = get_le16(pb);

  383.             len3 = get_le16(pb);

  384.             len4 = get_le16(pb);

  385.             len5 = get_le16(pb);

  386.             get_tag(s, "title"    , 0, len1);

  387.             get_tag(s, "author"   , 0, len2);

  388.             get_tag(s, "copyright", 0, len3);

  389.             get_tag(s, "comment"  , 0, len4);

  390.             url_fskip(pb, len5);

  391.         } else if (!guidcmp(&g, &stream_bitrate_guid)) {

  392.             int stream_count = get_le16(pb);

  393.             int j;

  394. 

  395. //            av_log(s, AV_LOG_ERROR, "stream bitrate properties\n");

  396. //            av_log(s, AV_LOG_ERROR, "streams %d\n", streams);

  397.             for(j = 0; j < stream_count; j++) {

  398.                 int flags, bitrate, stream_id;

  399. 

  400.                 flags= get_le16(pb);

  401.                 bitrate= get_le32(pb);

  402.                 stream_id= (flags & 0x7f);

  403. //                av_log(s, AV_LOG_ERROR, "flags: 0x%x stream id %d, bitrate %d\n", flags, stream_id, bitrate);

  404.                 asf->stream_bitrates[stream_id]= bitrate;

  405.             }

  406.         } else if (!guidcmp(&g, &ff_asf_extended_content_header)) {

  407.             int desc_count, i;

  408. 

  409.             desc_count = get_le16(pb);

  410.             for(i=0;i<desc_count;i++) {

  411.                     int name_len,value_type,value_len;

  412.                     char name[1024];

  413. 

  414.                     name_len = get_le16(pb);

  415.                     get_str16_nolen(pb, name_len, name, sizeof(name));

  416.                     value_type = get_le16(pb);

  417.                     value_len  = get_le16(pb);

  418.                     get_tag(s, name, value_type, value_len);

  419.             }

  420.         } else if (!guidcmp(&g, &ff_asf_metadata_header)) {

  421.             int n, stream_num, name_len, value_len, value_type, value_num;

  422.             n = get_le16(pb);

  423. 

  424.             for(i=0;i<n;i++) {

  425.                 char name[1024];

  426. 

  427.                 get_le16(pb); //lang_list_index

  428.                 stream_num= get_le16(pb);

  429.                 name_len=   get_le16(pb);

  430.                 value_type= get_le16(pb);

  431.                 value_len=  get_le32(pb);

  432. 

  433.                 get_str16_nolen(pb, name_len, name, sizeof(name));

  434. //av_log(s, AV_LOG_ERROR, "%d %d %d %d %d <%s>\n", i, stream_num, name_len, value_type, value_len, name);

  435.                 value_num= get_le16(pb);//we should use get_value() here but it does not work 2 is le16 here but le32 elsewhere

  436.                 url_fskip(pb, value_len - 2);

  437. 

  438.                 if(stream_num<128){

  439.                     if     (!strcmp(name, "AspectRatioX")) dar[stream_num].num= value_num;

  440.                     else if(!strcmp(name, "AspectRatioY")) dar[stream_num].den= value_num;

  441.                 }

  442.             }

  443.         } else if (!guidcmp(&g, &ff_asf_ext_stream_header)) {

  444.             int ext_len, payload_ext_ct, stream_ct;

  445.             uint32_t ext_d, leak_rate, stream_num;

  446. 

  447.             get_le64(pb); // starttime

  448.             get_le64(pb); // endtime

  449.             leak_rate = get_le32(pb); // leak-datarate

  450.             get_le32(pb); // bucket-datasize

  451.             get_le32(pb); // init-bucket-fullness

  452.             get_le32(pb); // alt-leak-datarate

  453.             get_le32(pb); // alt-bucket-datasize

  454.             get_le32(pb); // alt-init-bucket-fullness

  455.             get_le32(pb); // max-object-size

  456.             get_le32(pb); // flags (reliable,seekable,no_cleanpoints?,resend-live-cleanpoints, rest of bits reserved)

  457.             stream_num = get_le16(pb); // stream-num

  458.             get_le16(pb); // stream-language-id-index

  459.             get_le64(pb); // avg frametime in 100ns units

  460.             stream_ct = get_le16(pb); //stream-name-count

  461.             payload_ext_ct = get_le16(pb); //payload-extension-system-count

  462. 

  463.             if (stream_num < 128)

  464.                 bitrate[stream_num] = leak_rate;

  465. 

  466.             for (i=0; i<stream_ct; i++){

  467.                 get_le16(pb);

  468.                 ext_len = get_le16(pb);

  469.                 url_fseek(pb, ext_len, SEEK_CUR);

  470.             }

  471. 

  472.             for (i=0; i<payload_ext_ct; i++){

  473.                 get_guid(pb, &g);

  474.                 ext_d=get_le16(pb);

  475.                 ext_len=get_le32(pb);

  476.                 url_fseek(pb, ext_len, SEEK_CUR);

  477.             }

  478. 

  479.             // there could be a optional stream properties object to follow

  480.             // if so the next iteration will pick it up

  481.         } else if (!guidcmp(&g, &ff_asf_head1_guid)) {

  482.             int v1, v2;

  483.             get_guid(pb, &g);

  484.             v1 = get_le32(pb);

  485.             v2 = get_le16(pb);

  486. #if 0

  487.         } else if (!guidcmp(&g, &ff_asf_codec_comment_header)) {

  488.             int len, v1, n, num;

  489.             char str[256], *q;

  490.             char tag[16];

  491. 

  492.             get_guid(pb, &g);

  493.             print_guid(&g);

  494. 

  495.             n = get_le32(pb);

  496.             for(i=0;i<n;i++) {

  497.                 num = get_le16(pb); /* stream number */

  498.                 get_str16(pb, str, sizeof(str));

  499.                 get_str16(pb, str, sizeof(str));

  500.                 len = get_le16(pb);

  501.                 q = tag;

  502.                 while (len > 0) {

  503.                     v1 = get_byte(pb);

  504.                     if ((q - tag) < sizeof(tag) - 1)

  505.                         *q++ = v1;

  506.                     len--;

  507.                 }

  508.                 *q = '\0';

  509.             }

  510. #endif

  511.         } else if (url_feof(pb)) {

  512.             return -1;

  513.         } else {

  514.             url_fseek(pb, gsize - 24, SEEK_CUR);

  515.         }

  516.     }

  517.     get_guid(pb, &g);

  518.     get_le64(pb);

  519.     get_byte(pb);

  520.     get_byte(pb);

  521.     if (url_feof(pb))

  522.         return -1;

  523.     asf->data_offset = url_ftell(pb);

  524.     asf->packet_size_left = 0;

  525. 

  526. 

  527.     for(i=0; i<128; i++){

  528.         int stream_num= asf->asfid2avid[i];

  529.         if(stream_num>=0){

  530.             AVStream *st = s->streams[stream_num];

  531.             if (!st->codec->bit_rate)

  532.                 st->codec->bit_rate = bitrate[i];

  533.             if (dar[i].num > 0 && dar[i].den > 0)

  534.                 av_reduce(&st->sample_aspect_ratio.num,

  535.                           &st->sample_aspect_ratio.den,

  536.                           dar[i].num, dar[i].den, INT_MAX);

  537. //av_log(s, AV_LOG_ERROR, "dar %d:%d sar=%d:%d\n", dar[i].num, dar[i].den, st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);

  538.         }

  539.     }

  540. 

  541.     return 0;

  542. }

  543. 

  544. #define DO_2BITS(bits, var, defval) \

  545.     switch (bits & 3) \

  546.     { \

  547.     case 3: var = get_le32(pb); rsize += 4; break; \

  548.     case 2: var = get_le16(pb); rsize += 2; break; \

  549.     case 1: var = get_byte(pb); rsize++; break; \

  550.     default: var = defval; break; \

  551.     }

  552. 

  553. int ff_asf_get_packet(AVFormatContext *s, ByteIOContext *pb)

  554. {

  555.     ASFContext *asf = s->priv_data;

  556.     uint32_t packet_length, padsize;

  557.     int rsize = 8;

  558.     int c, d, e, off;

  559. 

  560.     off= (url_ftell(pb) - s->data_offset) % asf->packet_size + 3;

  561. 

  562.     c=d=e=-1;

  563.     while(off-- > 0){

  564.         c=d; d=e;

  565.         e= get_byte(pb);

  566.         if(c == 0x82 && !d && !e)

  567.             break;

  568.     }

  569. 

  570.     if (c != 0x82) {

  571.         if (!url_feof(pb))

  572.             av_log(s, AV_LOG_ERROR, "ff asf bad header %x  at:%"PRId64"\n", c, url_ftell(pb));

  573.     }

  574.     if ((c & 0x8f) == 0x82) {

  575.         if (d || e) {

  576.             if (!url_feof(pb))

  577.                 av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");

  578.             return -1;

  579.         }

  580.         c= get_byte(pb);

  581.         d= get_byte(pb);

  582.         rsize+=3;

  583.     }else{

  584.         url_fseek(pb, -1, SEEK_CUR); //FIXME

  585.     }

  586. 

  587.     asf->packet_flags    = c;

  588.     asf->packet_property = d;

  589. 

  590.     DO_2BITS(asf->packet_flags >> 5, packet_length, asf->packet_size);

  591.     DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored

  592.     DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length

  593. 

  594.     //the following checks prevent overflows and infinite loops

  595.     if(packet_length >= (1U<<29)){

  596.         av_log(s, AV_LOG_ERROR, "invalid packet_length %d at:%"PRId64"\n", packet_length, url_ftell(pb));

  597.         return -1;

  598.     }

  599.     if(padsize >= packet_length){

  600.         av_log(s, AV_LOG_ERROR, "invalid padsize %d at:%"PRId64"\n", padsize, url_ftell(pb));

  601.         return -1;

  602.     }

  603. 

  604.     asf->packet_timestamp = get_le32(pb);

  605.     get_le16(pb); /* duration */

  606.     // rsize has at least 11 bytes which have to be present

  607. 

  608.     if (asf->packet_flags & 0x01) {

  609.         asf->packet_segsizetype = get_byte(pb); rsize++;

  610.         asf->packet_segments = asf->packet_segsizetype & 0x3f;

  611.     } else {

  612.         asf->packet_segments = 1;

  613.         asf->packet_segsizetype = 0x80;

  614.     }

  615.     asf->packet_size_left = packet_length - padsize - rsize;

  616.     if (packet_length < asf->hdr.min_pktsize)

  617.         padsize += asf->hdr.min_pktsize - packet_length;

  618.     asf->packet_padsize = padsize;

  619.     dprintf(s, "packet: size=%d padsize=%d  left=%d\n", asf->packet_size, asf->packet_padsize, asf->packet_size_left);

  620.     return 0;

  621. }

  622. 

  623. /**

  624.  *

  625.  * @return <0 if error

  626.  */

  627. static int asf_read_frame_header(AVFormatContext *s, ByteIOContext *pb){

  628.     ASFContext *asf = s->priv_data;

  629.     int rsize = 1;

  630.     int num = get_byte(pb);

  631.     int64_t ts0, ts1;

  632. 

  633.     asf->packet_segments--;

  634.     asf->packet_key_frame = num >> 7;

  635.     asf->stream_index = asf->asfid2avid[num & 0x7f];

  636.     // sequence should be ignored!

  637.     DO_2BITS(asf->packet_property >> 4, asf->packet_seq, 0);

  638.     DO_2BITS(asf->packet_property >> 2, asf->packet_frag_offset, 0);

  639.     DO_2BITS(asf->packet_property, asf->packet_replic_size, 0);

  640. //printf("key:%d stream:%d seq:%d offset:%d replic_size:%d\n", asf->packet_key_frame, asf->stream_index, asf->packet_seq, //asf->packet_frag_offset, asf->packet_replic_size);

  641.     if (asf->packet_replic_size >= 8) {

  642.         asf->packet_obj_size = get_le32(pb);

  643.         if(asf->packet_obj_size >= (1<<24) || asf->packet_obj_size <= 0){

  644.             av_log(s, AV_LOG_ERROR, "packet_obj_size invalid\n");

  645.             return -1;

  646.         }

  647.         asf->packet_frag_timestamp = get_le32(pb); // timestamp

  648.         if(asf->packet_replic_size >= 8+38+4){

  649. //            for(i=0; i<asf->packet_replic_size-8; i++)

  650. //                av_log(s, AV_LOG_DEBUG, "%02X ",get_byte(pb));

  651. //            av_log(s, AV_LOG_DEBUG, "\n");

  652.             url_fskip(pb, 10);

  653.             ts0= get_le64(pb);

  654.             ts1= get_le64(pb);

  655.             url_fskip(pb, 12);

  656.             get_le32(pb);

  657.             url_fskip(pb, asf->packet_replic_size - 8 - 38 - 4);

  658.             if(ts0!= -1) asf->packet_frag_timestamp= ts0/10000;

  659.             else         asf->packet_frag_timestamp= AV_NOPTS_VALUE;

  660.         }else

  661.             url_fskip(pb, asf->packet_replic_size - 8);

  662.         rsize += asf->packet_replic_size; // FIXME - check validity

  663.     } else if (asf->packet_replic_size==1){

  664.         // multipacket - frag_offset is beginning timestamp

  665.         asf->packet_time_start = asf->packet_frag_offset;

  666.         asf->packet_frag_offset = 0;

  667.         asf->packet_frag_timestamp = asf->packet_timestamp;

  668. 

  669.         asf->packet_time_delta = get_byte(pb);

  670.         rsize++;

  671.     }else if(asf->packet_replic_size!=0){

  672.         av_log(s, AV_LOG_ERROR, "unexpected packet_replic_size of %d\n", asf->packet_replic_size);

  673.         return -1;

  674.     }

  675.     if (asf->packet_flags & 0x01) {

  676.         DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal

  677.         if(asf->packet_frag_size > asf->packet_size_left - rsize){

  678.             av_log(s, AV_LOG_ERROR, "packet_frag_size is invalid\n");

  679.             return -1;

  680.         }

  681.         //printf("Fragsize %d\n", asf->packet_frag_size);

  682.     } else {

  683.         asf->packet_frag_size = asf->packet_size_left - rsize;

  684.         //printf("Using rest  %d %d %d\n", asf->packet_frag_size, asf->packet_size_left, rsize);

  685.     }

  686.     if (asf->packet_replic_size == 1) {

  687.         asf->packet_multi_size = asf->packet_frag_size;

  688.         if (asf->packet_multi_size > asf->packet_size_left)

  689.             return -1;

  690.     }

  691.     asf->packet_size_left -= rsize;

  692.     //printf("___objsize____  %d   %d    rs:%d\n", asf->packet_obj_size, asf->packet_frag_offset, rsize);

  693. 

  694.     return 0;

  695. }

  696. 

  697. int ff_asf_parse_packet(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)

  698. {

  699.     ASFContext *asf = s->priv_data;

  700.     ASFStream *asf_st = 0;

  701.     for (;;) {

  702.         if(url_feof(pb))

  703.             return AVERROR_EOF;

  704.         if (asf->packet_size_left < FRAME_HEADER_SIZE

  705.             || asf->packet_segments < 1) {

  706.             //asf->packet_size_left <= asf->packet_padsize) {

  707.             int ret = asf->packet_size_left + asf->packet_padsize;

  708.             //printf("PacketLeftSize:%d  Pad:%d Pos:%"PRId64"\n", asf->packet_size_left, asf->packet_padsize, url_ftell(pb));

  709.             assert(ret>=0);

  710.             /* fail safe */

  711.             url_fskip(pb, ret);

  712. 

  713.             asf->packet_pos= url_ftell(pb);

  714.             if (asf->data_object_size != (uint64_t)-1 &&

  715.                 (asf->packet_pos - asf->data_object_offset >= asf->data_object_size))

  716.                 return AVERROR_EOF; /* Do not exceed the size of the data object */

  717.             return 1;

  718.         }

  719.         if (asf->packet_time_start == 0) {

  720.             if(asf_read_frame_header(s, pb) < 0){

  721.                 asf->packet_segments= 0;

  722.                 continue;

  723.             }

  724.             if (asf->stream_index < 0

  725.                 || s->streams[asf->stream_index]->discard >= AVDISCARD_ALL

  726.                 || (!asf->packet_key_frame && s->streams[asf->stream_index]->discard >= AVDISCARD_NONKEY)

  727.                 ) {

  728.                 asf->packet_time_start = 0;

  729.                 /* unhandled packet (should not happen) */

  730.                 url_fskip(pb, asf->packet_frag_size);

  731.                 asf->packet_size_left -= asf->packet_frag_size;

  732.                 if(asf->stream_index < 0)

  733.                     av_log(s, AV_LOG_ERROR, "ff asf skip %d (unknown stream)\n", asf->packet_frag_size);

  734.                 continue;

  735.             }

  736.             asf->asf_st = s->streams[asf->stream_index]->priv_data;

  737.         }

  738.         asf_st = asf->asf_st;

  739. 

  740.         if (asf->packet_replic_size == 1) {

  741.             // frag_offset is here used as the beginning timestamp

  742.             asf->packet_frag_timestamp = asf->packet_time_start;

  743.             asf->packet_time_start += asf->packet_time_delta;

  744.             asf->packet_obj_size = asf->packet_frag_size = get_byte(pb);

  745.             asf->packet_size_left--;

  746.             asf->packet_multi_size--;

  747.             if (asf->packet_multi_size < asf->packet_obj_size)

  748.             {

  749.                 asf->packet_time_start = 0;

  750.                 url_fskip(pb, asf->packet_multi_size);

  751.                 asf->packet_size_left -= asf->packet_multi_size;

  752.                 continue;

  753.             }

  754.             asf->packet_multi_size -= asf->packet_obj_size;

  755.             //printf("COMPRESS size  %d  %d  %d   ms:%d\n", asf->packet_obj_size, asf->packet_frag_timestamp, asf->packet_size_left, asf->packet_multi_size);

  756.         }

  757.         if(   /*asf->packet_frag_size == asf->packet_obj_size*/

  758.               asf_st->frag_offset + asf->packet_frag_size <= asf_st->pkt.size

  759.            && asf_st->frag_offset + asf->packet_frag_size > asf->packet_obj_size){

  760.             av_log(s, AV_LOG_INFO, "ignoring invalid packet_obj_size (%d %d %d %d)\n",

  761.                 asf_st->frag_offset, asf->packet_frag_size,

  762.                 asf->packet_obj_size, asf_st->pkt.size);

  763.             asf->packet_obj_size= asf_st->pkt.size;

  764.         }

  765. 

  766.         if (   asf_st->pkt.size != asf->packet_obj_size

  767.             || asf_st->frag_offset + asf->packet_frag_size > asf_st->pkt.size) { //FIXME is this condition sufficient?

  768.             if(asf_st->pkt.data){

  769.                 av_log(s, AV_LOG_INFO, "freeing incomplete packet size %d, new %d\n", asf_st->pkt.size, asf->packet_obj_size);

  770.                 asf_st->frag_offset = 0;

  771.                 av_free_packet(&asf_st->pkt);

  772.             }

  773.             /* new packet */

  774.             av_new_packet(&asf_st->pkt, asf->packet_obj_size);

  775.             asf_st->seq = asf->packet_seq;

  776.             asf_st->pkt.dts = asf->packet_frag_timestamp;

  777.             asf_st->pkt.stream_index = asf->stream_index;

  778.             asf_st->pkt.pos =

  779.             asf_st->packet_pos= asf->packet_pos;

  780. //printf("new packet: stream:%d key:%d packet_key:%d audio:%d size:%d\n",

  781. //asf->stream_index, asf->packet_key_frame, asf_st->pkt.flags & PKT_FLAG_KEY,

  782. //s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO, asf->packet_obj_size);

  783.             if (s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO)

  784.                 asf->packet_key_frame = 1;

  785.             if (asf->packet_key_frame)

  786.                 asf_st->pkt.flags |= PKT_FLAG_KEY;

  787.         }

  788. 

  789.         /* read data */

  790.         //printf("READ PACKET s:%d  os:%d  o:%d,%d  l:%d   DATA:%p\n",

  791.         //       asf->packet_size, asf_st->pkt.size, asf->packet_frag_offset,

  792.         //       asf_st->frag_offset, asf->packet_frag_size, asf_st->pkt.data);

  793.         asf->packet_size_left -= asf->packet_frag_size;

  794.         if (asf->packet_size_left < 0)

  795.             continue;

  796. 

  797.         if(   asf->packet_frag_offset >= asf_st->pkt.size

  798.            || asf->packet_frag_size > asf_st->pkt.size - asf->packet_frag_offset){

  799.             av_log(s, AV_LOG_ERROR, "packet fragment position invalid %u,%u not in %u\n",

  800.                 asf->packet_frag_offset, asf->packet_frag_size, asf_st->pkt.size);

  801.             continue;

  802.         }

  803. 

  804.         get_buffer(pb, asf_st->pkt.data + asf->packet_frag_offset,

  805.                    asf->packet_frag_size);

  806.         if (s->key && s->keylen == 20)

  807.             ff_asfcrypt_dec(s->key, asf_st->pkt.data + asf->packet_frag_offset,

  808.                             asf->packet_frag_size);

  809.         asf_st->frag_offset += asf->packet_frag_size;

  810.         /* test if whole packet is read */

  811.         if (asf_st->frag_offset == asf_st->pkt.size) {

  812.             //workaround for macroshit radio DVR-MS files

  813.             if(   s->streams[asf->stream_index]->codec->codec_id == CODEC_ID_MPEG2VIDEO

  814.                && asf_st->pkt.size > 100){

  815.                 int i;

  816.                 for(i=0; i<asf_st->pkt.size && !asf_st->pkt.data[i]; i++);

  817.                 if(i == asf_st->pkt.size){

  818.                     av_log(s, AV_LOG_DEBUG, "discarding ms fart\n");

  819.                     asf_st->frag_offset = 0;

  820.                     av_free_packet(&asf_st->pkt);

  821.                     continue;

  822.                 }

  823.             }

  824. 

  825.             /* return packet */

  826.             if (asf_st->ds_span > 1) {

  827.               if(asf_st->pkt.size != asf_st->ds_packet_size * asf_st->ds_span){

  828.                     av_log(s, AV_LOG_ERROR, "pkt.size != ds_packet_size * ds_span (%d %d %d)\n", asf_st->pkt.size, asf_st->ds_packet_size, asf_st->ds_span);

  829.               }else{

  830.                 /* packet descrambling */

  831.                 uint8_t *newdata = av_malloc(asf_st->pkt.size);

  832.                 if (newdata) {

  833.                     int offset = 0;

  834.                     while (offset < asf_st->pkt.size) {

  835.                         int off = offset / asf_st->ds_chunk_size;

  836.                         int row = off / asf_st->ds_span;

  837.                         int col = off % asf_st->ds_span;

  838.                         int idx = row + col * asf_st->ds_packet_size / asf_st->ds_chunk_size;

  839.                         //printf("off:%d  row:%d  col:%d  idx:%d\n", off, row, col, idx);

  840. 

  841.                         assert(offset + asf_st->ds_chunk_size <= asf_st->pkt.size);

  842.                         assert(idx+1 <= asf_st->pkt.size / asf_st->ds_chunk_size);

  843.                         memcpy(newdata + offset,

  844.                                asf_st->pkt.data + idx * asf_st->ds_chunk_size,

  845.                                asf_st->ds_chunk_size);

  846.                         offset += asf_st->ds_chunk_size;

  847.                     }

  848.                     av_free(asf_st->pkt.data);

  849.                     asf_st->pkt.data = newdata;

  850.                 }

  851.               }

  852.             }

  853.             asf_st->frag_offset = 0;

  854.             *pkt= asf_st->pkt;

  855.             //printf("packet %d %d\n", asf_st->pkt.size, asf->packet_frag_size);

  856.             asf_st->pkt.size = 0;

  857.             asf_st->pkt.data = 0;

  858.             break; // packet completed

  859.         }

  860.     }

  861.     return 0;

  862. }

  863. 

  864. static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)

  865. {

  866.     ASFContext *asf = s->priv_data;

  867. 

  868.     for (;;) {

  869.         int ret;

  870. 

  871.         /* parse cached packets, if any */

  872.         if ((ret = ff_asf_parse_packet(s, s->pb, pkt)) <= 0)

  873.             return ret;

  874.         if ((ret = ff_asf_get_packet(s, s->pb)) < 0)

  875.             assert(asf->packet_size_left < FRAME_HEADER_SIZE || asf->packet_segments < 1);

  876.         asf->packet_time_start = 0;

  877.     }

  878. 

  879.     return 0;

  880. }

  881. 

  882. // Added to support seeking after packets have been read

  883. // If information is not reset, read_packet fails due to

  884. // leftover information from previous reads

  885. static void asf_reset_header(AVFormatContext *s)

  886. {

  887.     ASFContext *asf = s->priv_data;

  888.     ASFStream *asf_st;

  889.     int i;

  890. 

  891.     asf->packet_nb_frames = 0;

  892.     asf->packet_size_left = 0;

  893.     asf->packet_segments = 0;

  894.     asf->packet_flags = 0;

  895.     asf->packet_property = 0;

  896.     asf->packet_timestamp = 0;

  897.     asf->packet_segsizetype = 0;

  898.     asf->packet_segments = 0;

  899.     asf->packet_seq = 0;

  900.     asf->packet_replic_size = 0;

  901.     asf->packet_key_frame = 0;

  902.     asf->packet_padsize = 0;

  903.     asf->packet_frag_offset = 0;

  904.     asf->packet_frag_size = 0;

  905.     asf->packet_frag_timestamp = 0;

  906.     asf->packet_multi_size = 0;

  907.     asf->packet_obj_size = 0;

  908.     asf->packet_time_delta = 0;

  909.     asf->packet_time_start = 0;

  910. 

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

  912.         asf_st= s->streams[i]->priv_data;

  913.         av_free_packet(&asf_st->pkt);

  914.         asf_st->frag_offset=0;

  915.         asf_st->seq=0;

  916.     }

  917.     asf->asf_st= NULL;

  918. }

  919. 

  920. static int asf_read_close(AVFormatContext *s)

  921. {

  922.     int i;

  923. 

  924.     asf_reset_header(s);

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

  926.         AVStream *st = s->streams[i];

  927.         av_free(st->codec->palctrl);

  928.     }

  929.     return 0;

  930. }

  931. 

  932. static int64_t asf_read_pts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit)

  933. {

  934.     ASFContext *asf = s->priv_data;

  935.     AVPacket pkt1, *pkt = &pkt1;

  936.     ASFStream *asf_st;

  937.     int64_t pts;

  938.     int64_t pos= *ppos;

  939.     int i;

  940.     int64_t start_pos[s->nb_streams];

  941. 

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

  943.         start_pos[i]= pos;

  944.     }

  945. 

  946.     pos= (pos+asf->packet_size-1-s->data_offset)/asf->packet_size*asf->packet_size+ s->data_offset;

  947.     *ppos= pos;

  948.     url_fseek(s->pb, pos, SEEK_SET);

  949. 

  950. //printf("asf_read_pts\n");

  951.     asf_reset_header(s);

  952.     for(;;){

  953.         if (av_read_frame(s, pkt) < 0){

  954.             av_log(s, AV_LOG_INFO, "asf_read_pts failed\n");

  955.             return AV_NOPTS_VALUE;

  956.         }

  957. 

  958.         pts= pkt->pts;

  959. 

  960.         av_free_packet(pkt);

  961.         if(pkt->flags&PKT_FLAG_KEY){

  962.             i= pkt->stream_index;

  963. 

  964.             asf_st= s->streams[i]->priv_data;

  965. 

  966. //            assert((asf_st->packet_pos - s->data_offset) % asf->packet_size == 0);

  967.             pos= asf_st->packet_pos;

  968. 

  969.             av_add_index_entry(s->streams[i], pos, pts, pkt->size, pos - start_pos[i] + 1, AVINDEX_KEYFRAME);

  970.             start_pos[i]= asf_st->packet_pos + 1;

  971. 

  972.             if(pkt->stream_index == stream_index)

  973.                break;

  974.         }

  975.     }

  976. 

  977.     *ppos= pos;

  978. //printf("found keyframe at %"PRId64" stream %d stamp:%"PRId64"\n", *ppos, stream_index, pts);

  979. 

  980.     return pts;

  981. }

  982. 

  983. static void asf_build_simple_index(AVFormatContext *s, int stream_index)

  984. {

  985.     ff_asf_guid g;

  986.     ASFContext *asf = s->priv_data;

  987.     int64_t current_pos= url_ftell(s->pb);

  988.     int i;

  989. 

  990.     url_fseek(s->pb, asf->data_object_offset + asf->data_object_size, SEEK_SET);

  991.     get_guid(s->pb, &g);

  992.     if (!guidcmp(&g, &index_guid)) {

  993.         int64_t itime;

  994.         int pct, ict;

  995.         int64_t av_unused gsize= get_le64(s->pb);

  996.         get_guid(s->pb, &g);

  997.         itime=get_le64(s->pb);

  998.         pct=get_le32(s->pb);

  999.         ict=get_le32(s->pb);

  1000.         av_log(s, AV_LOG_DEBUG, "itime:0x%"PRIx64", pct:%d, ict:%d\n",itime,pct,ict);

  1001. 

  1002.         for (i=0;i<ict;i++){

  1003.             int pktnum=get_le32(s->pb);

  1004.             int pktct =get_le16(s->pb);

  1005.             int64_t pos      = s->data_offset + asf->packet_size*(int64_t)pktnum;

  1006.             int64_t index_pts= av_rescale(itime, i, 10000);

  1007. 

  1008.             av_log(s, AV_LOG_DEBUG, "pktnum:%d, pktct:%d\n", pktnum, pktct);

  1009.             av_add_index_entry(s->streams[stream_index], pos, index_pts, asf->packet_size, 0, AVINDEX_KEYFRAME);

  1010.         }

  1011.         asf->index_read= 1;

  1012.     }

  1013.     url_fseek(s->pb, current_pos, SEEK_SET);

  1014. }

  1015. 

  1016. static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)

  1017. {

  1018.     ASFContext *asf = s->priv_data;

  1019.     AVStream *st = s->streams[stream_index];

  1020.     int64_t pos;

  1021.     int index;

  1022. 

  1023.     if (asf->packet_size <= 0)

  1024.         return -1;

  1025. 

  1026.     /* Try using the protocol's read_seek if available */

  1027.     if(s->pb) {

  1028.         int ret = av_url_read_fseek(s->pb, stream_index, pts, flags);

  1029.         if(ret >= 0)

  1030.             asf_reset_header(s);

  1031.         if (ret != AVERROR(ENOSYS))

  1032.             return ret;

  1033.     }

  1034. 

  1035.     if (!asf->index_read)

  1036.         asf_build_simple_index(s, stream_index);

  1037. 

  1038.     if(!(asf->index_read && st->index_entries)){

  1039.         if(av_seek_frame_binary(s, stream_index, pts, flags)<0)

  1040.             return -1;

  1041.     }else{

  1042.         index= av_index_search_timestamp(st, pts, flags);

  1043.         if(index<0)

  1044.             return -1;

  1045. 

  1046.         /* find the position */

  1047.         pos = st->index_entries[index].pos;

  1048. 

  1049.     // various attempts to find key frame have failed so far

  1050.     //    asf_reset_header(s);

  1051.     //    url_fseek(s->pb, pos, SEEK_SET);

  1052.     //    key_pos = pos;

  1053.     //     for(i=0;i<16;i++){

  1054.     //         pos = url_ftell(s->pb);

  1055.     //         if (av_read_frame(s, &pkt) < 0){

  1056.     //             av_log(s, AV_LOG_INFO, "seek failed\n");

  1057.     //             return -1;

  1058.     //         }

  1059.     //         asf_st = s->streams[stream_index]->priv_data;

  1060.     //         pos += st->parser->frame_offset;

  1061.     //

  1062.     //         if (pkt.size > b) {

  1063.     //             b = pkt.size;

  1064.     //             key_pos = pos;

  1065.     //         }

  1066.     //

  1067.     //         av_free_packet(&pkt);

  1068.     //     }

  1069. 

  1070.         /* do the seek */

  1071.         av_log(s, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos);

  1072.         url_fseek(s->pb, pos, SEEK_SET);

  1073.     }

  1074.     asf_reset_header(s);

  1075.     return 0;

  1076. }

  1077. 

  1078. AVInputFormat asf_demuxer = {

  1079.     "asf",

  1080.     NULL_IF_CONFIG_SMALL("ASF format"),

  1081.     sizeof(ASFContext),

  1082.     asf_probe,

  1083.     asf_read_header,

  1084.     asf_read_packet,

  1085.     asf_read_close,

  1086.     asf_read_seek,

  1087.     asf_read_pts,

  1088.     .metadata_conv = ff_asf_metadata_conv,

  1089. };