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FFmpeg/libavformat/nutdec.c

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  1. /*

  2.  * "NUT" Container Format demuxer

  3.  * Copyright (c) 2004-2006 Michael Niedermayer

  4.  * Copyright (c) 2003 Alex Beregszaszi

  5.  *

  6.  * This file is part of FFmpeg.

  7.  *

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

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

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

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

  12.  *

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

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

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

  16.  * Lesser General Public License for more details.

  17.  *

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

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

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

  21.  */

  22. 

  23. #include "libavutil/avstring.h"

  24. #include "libavutil/avassert.h"

  25. #include "libavutil/bswap.h"

  26. #include "libavutil/dict.h"

  27. #include "libavutil/mathematics.h"

  28. #include "libavutil/tree.h"

  29. #include "avio_internal.h"

  30. #include "nut.h"

  31. #include "riff.h"

  32. 

  33. #define NUT_MAX_STREAMS 256    /* arbitrary sanity check value */

  34. 

  35. static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,

  36.                                   int64_t *pos_arg, int64_t pos_limit);

  37. 

  38. static int get_str(AVIOContext *bc, char *string, unsigned int maxlen)

  39. {

  40.     unsigned int len = ffio_read_varlen(bc);

  41. 

  42.     if (len && maxlen)

  43.         avio_read(bc, string, FFMIN(len, maxlen));

  44.     while (len > maxlen) {

  45.         avio_r8(bc);

  46.         len--;

  47.     }

  48. 

  49.     if (maxlen)

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

  51. 

  52.     if (maxlen == len)

  53.         return -1;

  54.     else

  55.         return 0;

  56. }

  57. 

  58. static int64_t get_s(AVIOContext *bc)

  59. {

  60.     int64_t v = ffio_read_varlen(bc) + 1;

  61. 

  62.     if (v & 1)

  63.         return -(v >> 1);

  64.     else

  65.         return  (v >> 1);

  66. }

  67. 

  68. static uint64_t get_fourcc(AVIOContext *bc)

  69. {

  70.     unsigned int len = ffio_read_varlen(bc);

  71. 

  72.     if (len == 2)

  73.         return avio_rl16(bc);

  74.     else if (len == 4)

  75.         return avio_rl32(bc);

  76.     else {

  77.         av_log(NULL, AV_LOG_ERROR, "Unsupported fourcc length %d\n", len);

  78.         return -1;

  79.     }

  80. }

  81. 

  82. #ifdef TRACE

  83. static inline uint64_t get_v_trace(AVIOContext *bc, const char *file,

  84.                                    const char *func, int line)

  85. {

  86.     uint64_t v = ffio_read_varlen(bc);

  87. 

  88.     av_log(NULL, AV_LOG_DEBUG, "get_v %5"PRId64" / %"PRIX64" in %s %s:%d\n",

  89.            v, v, file, func, line);

  90.     return v;

  91. }

  92. 

  93. static inline int64_t get_s_trace(AVIOContext *bc, const char *file,

  94.                                   const char *func, int line)

  95. {

  96.     int64_t v = get_s(bc);

  97. 

  98.     av_log(NULL, AV_LOG_DEBUG, "get_s %5"PRId64" / %"PRIX64" in %s %s:%d\n",

  99.            v, v, file, func, line);

  100.     return v;

  101. }

  102. 

  103. static inline uint64_t get_4cc_trace(AVIOContext *bc, char *file,

  104.                                     char *func, int line)

  105. {

  106.     uint64_t v = get_fourcc(bc);

  107. 

  108.     av_log(NULL, AV_LOG_DEBUG, "get_fourcc %5"PRId64" / %"PRIX64" in %s %s:%d\n",

  109.            v, v, file, func, line);

  110.     return v;

  111. }

  112. #define ffio_read_varlen(bc) get_v_trace(bc,  __FILE__, __PRETTY_FUNCTION__, __LINE__)

  113. #define get_s(bc)            get_s_trace(bc,  __FILE__, __PRETTY_FUNCTION__, __LINE__)

  114. #define get_fourcc(bc)       get_4cc_trace(bc, __FILE__, __PRETTY_FUNCTION__, __LINE__)

  115. #endif

  116. 

  117. static int get_packetheader(NUTContext *nut, AVIOContext *bc,

  118.                             int calculate_checksum, uint64_t startcode)

  119. {

  120.     int64_t size;

  121. //    start = avio_tell(bc) - 8;

  122. 

  123.     startcode = av_be2ne64(startcode);

  124.     startcode = ff_crc04C11DB7_update(0, (uint8_t*) &startcode, 8);

  125. 

  126.     ffio_init_checksum(bc, ff_crc04C11DB7_update, startcode);

  127.     size = ffio_read_varlen(bc);

  128.     if (size > 4096)

  129.         avio_rb32(bc);

  130.     if (ffio_get_checksum(bc) && size > 4096)

  131.         return -1;

  132. 

  133.     ffio_init_checksum(bc, calculate_checksum ? ff_crc04C11DB7_update : NULL, 0);

  134. 

  135.     return size;

  136. }

  137. 

  138. static uint64_t find_any_startcode(AVIOContext *bc, int64_t pos)

  139. {

  140.     uint64_t state = 0;

  141. 

  142.     if (pos >= 0)

  143.         /* Note, this may fail if the stream is not seekable, but that should

  144.          * not matter, as in this case we simply start where we currently are */

  145.         avio_seek(bc, pos, SEEK_SET);

  146.     while (!url_feof(bc)) {

  147.         state = (state << 8) | avio_r8(bc);

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

  149.             continue;

  150.         switch (state) {

  151.         case MAIN_STARTCODE:

  152.         case STREAM_STARTCODE:

  153.         case SYNCPOINT_STARTCODE:

  154.         case INFO_STARTCODE:

  155.         case INDEX_STARTCODE:

  156.             return state;

  157.         }

  158.     }

  159. 

  160.     return 0;

  161. }

  162. 

  163. /**

  164.  * Find the given startcode.

  165.  * @param code the startcode

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

  167.  * @return the position of the startcode or -1 if not found

  168.  */

  169. static int64_t find_startcode(AVIOContext *bc, uint64_t code, int64_t pos)

  170. {

  171.     for (;;) {

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

  173.         if (startcode == code)

  174.             return avio_tell(bc) - 8;

  175.         else if (startcode == 0)

  176.             return -1;

  177.         pos = -1;

  178.     }

  179. }

  180. 

  181. static int nut_probe(AVProbeData *p)

  182. {

  183.     int i;

  184.     uint64_t code = 0;

  185. 

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

  187.         code = (code << 8) | p->buf[i];

  188.         if (code == MAIN_STARTCODE)

  189.             return AVPROBE_SCORE_MAX;

  190.     }

  191.     return 0;

  192. }

  193. 

  194. #define GET_V(dst, check)                                                     \

  195.     do {                                                                      \

  196.         tmp = ffio_read_varlen(bc);                                           \

  197.         if (!(check)) {                                                       \

  198.             av_log(s, AV_LOG_ERROR, "Error " #dst " is (%"PRId64")\n", tmp);  \

  199.             return AVERROR_INVALIDDATA;                                       \

  200.         }                                                                     \

  201.         dst = tmp;                                                            \

  202.     } while (0)

  203. 

  204. static int skip_reserved(AVIOContext *bc, int64_t pos)

  205. {

  206.     pos -= avio_tell(bc);

  207.     if (pos < 0) {

  208.         avio_seek(bc, pos, SEEK_CUR);

  209.         return AVERROR_INVALIDDATA;

  210.     } else {

  211.         while (pos--)

  212.             avio_r8(bc);

  213.         return 0;

  214.     }

  215. }

  216. 

  217. static int decode_main_header(NUTContext *nut)

  218. {

  219.     AVFormatContext *s = nut->avf;

  220.     AVIOContext *bc    = s->pb;

  221.     uint64_t tmp, end;

  222.     unsigned int stream_count;

  223.     int i, j, count;

  224.     int tmp_stream, tmp_mul, tmp_pts, tmp_size, tmp_res, tmp_head_idx;

  225. 

  226.     end  = get_packetheader(nut, bc, 1, MAIN_STARTCODE);

  227.     end += avio_tell(bc);

  228. 

  229.     tmp = ffio_read_varlen(bc);

  230.     if (tmp < 2 && tmp > NUT_VERSION) {

  231.         av_log(s, AV_LOG_ERROR, "Version %"PRId64" not supported.\n",

  232.                tmp);

  233.         return AVERROR(ENOSYS);

  234.     }

  235.     nut->version = tmp;

  236.     if (nut->version > 3)

  237.         nut->minor_version = ffio_read_varlen(bc);

  238. 

  239.     GET_V(stream_count, tmp > 0 && tmp <= NUT_MAX_STREAMS);

  240. 

  241.     nut->max_distance = ffio_read_varlen(bc);

  242.     if (nut->max_distance > 65536) {

  243.         av_log(s, AV_LOG_DEBUG, "max_distance %d\n", nut->max_distance);

  244.         nut->max_distance = 65536;

  245.     }

  246. 

  247.     GET_V(nut->time_base_count, tmp > 0 && tmp < INT_MAX / sizeof(AVRational));

  248.     nut->time_base = av_malloc(nut->time_base_count * sizeof(AVRational));

  249.     if (!nut->time_base)

  250.         return AVERROR(ENOMEM);

  251. 

  252.     for (i = 0; i < nut->time_base_count; i++) {

  253.         GET_V(nut->time_base[i].num, tmp > 0 && tmp < (1ULL << 31));

  254.         GET_V(nut->time_base[i].den, tmp > 0 && tmp < (1ULL << 31));

  255.         if (av_gcd(nut->time_base[i].num, nut->time_base[i].den) != 1) {

  256.             av_log(s, AV_LOG_ERROR, "time base invalid\n");

  257.             return AVERROR_INVALIDDATA;

  258.         }

  259.     }

  260.     tmp_pts      = 0;

  261.     tmp_mul      = 1;

  262.     tmp_stream   = 0;

  263.     tmp_head_idx = 0;

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

  265.         int tmp_flags  = ffio_read_varlen(bc);

  266.         int tmp_fields = ffio_read_varlen(bc);

  267. 

  268.         if (tmp_fields > 0)

  269.             tmp_pts = get_s(bc);

  270.         if (tmp_fields > 1)

  271.             tmp_mul = ffio_read_varlen(bc);

  272.         if (tmp_fields > 2)

  273.             tmp_stream = ffio_read_varlen(bc);

  274.         if (tmp_fields > 3)

  275.             tmp_size = ffio_read_varlen(bc);

  276.         else

  277.             tmp_size = 0;

  278.         if (tmp_fields > 4)

  279.             tmp_res = ffio_read_varlen(bc);

  280.         else

  281.             tmp_res = 0;

  282.         if (tmp_fields > 5)

  283.             count = ffio_read_varlen(bc);

  284.         else

  285.             count = tmp_mul - tmp_size;

  286.         if (tmp_fields > 6)

  287.             get_s(bc);

  288.         if (tmp_fields > 7)

  289.             tmp_head_idx = ffio_read_varlen(bc);

  290. 

  291.         while (tmp_fields-- > 8)

  292.             ffio_read_varlen(bc);

  293. 

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

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

  296.             return AVERROR_INVALIDDATA;

  297.         }

  298.         if (tmp_stream >= stream_count) {

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

  300.             return AVERROR_INVALIDDATA;

  301.         }

  302. 

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

  304.             if (i == 'N') {

  305.                 nut->frame_code[i].flags = FLAG_INVALID;

  306.                 j--;

  307.                 continue;

  308.             }

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

  310.             nut->frame_code[i].pts_delta      = tmp_pts;

  311.             nut->frame_code[i].stream_id      = tmp_stream;

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

  313.             nut->frame_code[i].size_lsb       = tmp_size + j;

  314.             nut->frame_code[i].reserved_count = tmp_res;

  315.             nut->frame_code[i].header_idx     = tmp_head_idx;

  316.         }

  317.     }

  318.     av_assert0(nut->frame_code['N'].flags == FLAG_INVALID);

  319. 

  320.     if (end > avio_tell(bc) + 4) {

  321.         int rem = 1024;

  322.         GET_V(nut->header_count, tmp < 128U);

  323.         nut->header_count++;

  324.         for (i = 1; i < nut->header_count; i++) {

  325.             uint8_t *hdr;

  326.             GET_V(nut->header_len[i], tmp > 0 && tmp < 256);

  327.             rem -= nut->header_len[i];

  328.             if (rem < 0) {

  329.                 av_log(s, AV_LOG_ERROR, "invalid elision header\n");

  330.                 return AVERROR_INVALIDDATA;

  331.             }

  332.             hdr = av_malloc(nut->header_len[i]);

  333.             if (!hdr)

  334.                 return AVERROR(ENOMEM);

  335.             avio_read(bc, hdr, nut->header_len[i]);

  336.             nut->header[i] = hdr;

  337.         }

  338.         av_assert0(nut->header_len[0] == 0);

  339.     }

  340. 

  341.     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {

  342.         av_log(s, AV_LOG_ERROR, "main header checksum mismatch\n");

  343.         return AVERROR_INVALIDDATA;

  344.     }

  345. 

  346.     nut->stream = av_calloc(stream_count, sizeof(StreamContext));

  347.     if (!nut->stream)

  348.         return AVERROR(ENOMEM);

  349.     for (i = 0; i < stream_count; i++)

  350.         avformat_new_stream(s, NULL);

  351. 

  352.     return 0;

  353. }

  354. 

  355. static int decode_stream_header(NUTContext *nut)

  356. {

  357.     AVFormatContext *s = nut->avf;

  358.     AVIOContext *bc    = s->pb;

  359.     StreamContext *stc;

  360.     int class, stream_id;

  361.     uint64_t tmp, end;

  362.     AVStream *st;

  363. 

  364.     end  = get_packetheader(nut, bc, 1, STREAM_STARTCODE);

  365.     end += avio_tell(bc);

  366. 

  367.     GET_V(stream_id, tmp < s->nb_streams && !nut->stream[tmp].time_base);

  368.     stc = &nut->stream[stream_id];

  369.     st  = s->streams[stream_id];

  370.     if (!st)

  371.         return AVERROR(ENOMEM);

  372. 

  373.     class                = ffio_read_varlen(bc);

  374.     tmp                  = get_fourcc(bc);

  375.     st->codec->codec_tag = tmp;

  376.     switch (class) {

  377.     case 0:

  378.         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

  379.         st->codec->codec_id   = av_codec_get_id((const AVCodecTag * const []) {

  380.                                                     ff_nut_video_tags,

  381.                                                     ff_codec_bmp_tags,

  382.                                                     0

  383.                                                 },

  384.                                                 tmp);

  385.         break;

  386.     case 1:

  387.         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

  388.         st->codec->codec_id   = av_codec_get_id((const AVCodecTag * const []) {

  389.                                                     ff_nut_audio_tags,

  390.                                                     ff_codec_wav_tags,

  391.                                                     0

  392.                                                 },

  393.                                                 tmp);

  394.         break;

  395.     case 2:

  396.         st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;

  397.         st->codec->codec_id   = ff_codec_get_id(ff_nut_subtitle_tags, tmp);

  398.         break;

  399.     case 3:

  400.         st->codec->codec_type = AVMEDIA_TYPE_DATA;

  401.         st->codec->codec_id   = ff_codec_get_id(ff_nut_data_tags, tmp);

  402.         break;

  403.     default:

  404.         av_log(s, AV_LOG_ERROR, "unknown stream class (%d)\n", class);

  405.         return AVERROR(ENOSYS);

  406.     }

  407.     if (class < 3 && st->codec->codec_id == AV_CODEC_ID_NONE)

  408.         av_log(s, AV_LOG_ERROR,

  409.                "Unknown codec tag '0x%04x' for stream number %d\n",

  410.                (unsigned int) tmp, stream_id);

  411. 

  412.     GET_V(stc->time_base_id, tmp < nut->time_base_count);

  413.     GET_V(stc->msb_pts_shift, tmp < 16);

  414.     stc->max_pts_distance = ffio_read_varlen(bc);

  415.     GET_V(stc->decode_delay, tmp < 1000); // sanity limit, raise this if Moore's law is true

  416.     st->codec->has_b_frames = stc->decode_delay;

  417.     ffio_read_varlen(bc); // stream flags

  418. 

  419.     GET_V(st->codec->extradata_size, tmp < (1 << 30));

  420.     if (st->codec->extradata_size) {

  421.         if (ff_get_extradata(st->codec, bc, st->codec->extradata_size) < 0)

  422.             return AVERROR(ENOMEM);

  423.     }

  424. 

  425.     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

  426.         GET_V(st->codec->width,  tmp > 0);

  427.         GET_V(st->codec->height, tmp > 0);

  428.         st->sample_aspect_ratio.num = ffio_read_varlen(bc);

  429.         st->sample_aspect_ratio.den = ffio_read_varlen(bc);

  430.         if ((!st->sample_aspect_ratio.num) != (!st->sample_aspect_ratio.den)) {

  431.             av_log(s, AV_LOG_ERROR, "invalid aspect ratio %d/%d\n",

  432.                    st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);

  433.             return AVERROR_INVALIDDATA;

  434.         }

  435.         ffio_read_varlen(bc); /* csp type */

  436.     } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {

  437.         GET_V(st->codec->sample_rate, tmp > 0);

  438.         ffio_read_varlen(bc); // samplerate_den

  439.         GET_V(st->codec->channels, tmp > 0);

  440.     }

  441.     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {

  442.         av_log(s, AV_LOG_ERROR,

  443.                "stream header %d checksum mismatch\n", stream_id);

  444.         return AVERROR_INVALIDDATA;

  445.     }

  446.     stc->time_base = &nut->time_base[stc->time_base_id];

  447.     avpriv_set_pts_info(s->streams[stream_id], 63, stc->time_base->num,

  448.                         stc->time_base->den);

  449.     return 0;

  450. }

  451. 

  452. static void set_disposition_bits(AVFormatContext *avf, char *value,

  453.                                  int stream_id)

  454. {

  455.     int flag = 0, i;

  456. 

  457.     for (i = 0; ff_nut_dispositions[i].flag; ++i)

  458.         if (!strcmp(ff_nut_dispositions[i].str, value))

  459.             flag = ff_nut_dispositions[i].flag;

  460.     if (!flag)

  461.         av_log(avf, AV_LOG_INFO, "unknown disposition type '%s'\n", value);

  462.     for (i = 0; i < avf->nb_streams; ++i)

  463.         if (stream_id == i || stream_id == -1)

  464.             avf->streams[i]->disposition |= flag;

  465. }

  466. 

  467. static int decode_info_header(NUTContext *nut)

  468. {

  469.     AVFormatContext *s = nut->avf;

  470.     AVIOContext *bc    = s->pb;

  471.     uint64_t tmp, chapter_start, chapter_len;

  472.     unsigned int stream_id_plus1, count;

  473.     int chapter_id, i;

  474.     int64_t value, end;

  475.     char name[256], str_value[1024], type_str[256];

  476.     const char *type;

  477.     AVChapter *chapter      = NULL;

  478.     AVStream *st            = NULL;

  479.     AVDictionary **metadata = NULL;

  480. 

  481.     end  = get_packetheader(nut, bc, 1, INFO_STARTCODE);

  482.     end += avio_tell(bc);

  483. 

  484.     GET_V(stream_id_plus1, tmp <= s->nb_streams);

  485.     chapter_id    = get_s(bc);

  486.     chapter_start = ffio_read_varlen(bc);

  487.     chapter_len   = ffio_read_varlen(bc);

  488.     count         = ffio_read_varlen(bc);

  489. 

  490.     if (chapter_id && !stream_id_plus1) {

  491.         int64_t start = chapter_start / nut->time_base_count;

  492.         chapter = avpriv_new_chapter(s, chapter_id,

  493.                                      nut->time_base[chapter_start %

  494.                                                     nut->time_base_count],

  495.                                      start, start + chapter_len, NULL);

  496.         metadata = &chapter->metadata;

  497.     } else if (stream_id_plus1) {

  498.         st       = s->streams[stream_id_plus1 - 1];

  499.         metadata = &st->metadata;

  500.     } else

  501.         metadata = &s->metadata;

  502. 

  503.     for (i = 0; i < count; i++) {

  504.         get_str(bc, name, sizeof(name));

  505.         value = get_s(bc);

  506.         if (value == -1) {

  507.             type = "UTF-8";

  508.             get_str(bc, str_value, sizeof(str_value));

  509.         } else if (value == -2) {

  510.             get_str(bc, type_str, sizeof(type_str));

  511.             type = type_str;

  512.             get_str(bc, str_value, sizeof(str_value));

  513.         } else if (value == -3) {

  514.             type  = "s";

  515.             value = get_s(bc);

  516.         } else if (value == -4) {

  517.             type  = "t";

  518.             value = ffio_read_varlen(bc);

  519.         } else if (value < -4) {

  520.             type = "r";

  521.             get_s(bc);

  522.         } else {

  523.             type = "v";

  524.         }

  525. 

  526.         if (stream_id_plus1 > s->nb_streams) {

  527.             av_log(s, AV_LOG_ERROR, "invalid stream id for info packet\n");

  528.             continue;

  529.         }

  530. 

  531.         if (!strcmp(type, "UTF-8")) {

  532.             if (chapter_id == 0 && !strcmp(name, "Disposition")) {

  533.                 set_disposition_bits(s, str_value, stream_id_plus1 - 1);

  534.                 continue;

  535.             }

  536. 

  537.             if (stream_id_plus1 && !strcmp(name, "r_frame_rate")) {

  538.                 sscanf(str_value, "%d/%d", &st->r_frame_rate.num, &st->r_frame_rate.den);

  539.                 if (st->r_frame_rate.num >= 1000LL*st->r_frame_rate.den)

  540.                     st->r_frame_rate.num = st->r_frame_rate.den = 0;

  541.                 continue;

  542.             }

  543. 

  544.             if (metadata && av_strcasecmp(name, "Uses") &&

  545.                 av_strcasecmp(name, "Depends") && av_strcasecmp(name, "Replaces"))

  546.                 av_dict_set(metadata, name, str_value, 0);

  547.         }

  548.     }

  549. 

  550.     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {

  551.         av_log(s, AV_LOG_ERROR, "info header checksum mismatch\n");

  552.         return AVERROR_INVALIDDATA;

  553.     }

  554.     return 0;

  555. }

  556. 

  557. static int decode_syncpoint(NUTContext *nut, int64_t *ts, int64_t *back_ptr)

  558. {

  559.     AVFormatContext *s = nut->avf;

  560.     AVIOContext *bc    = s->pb;

  561.     int64_t end;

  562.     uint64_t tmp;

  563.     int ret;

  564. 

  565.     nut->last_syncpoint_pos = avio_tell(bc) - 8;

  566. 

  567.     end  = get_packetheader(nut, bc, 1, SYNCPOINT_STARTCODE);

  568.     end += avio_tell(bc);

  569. 

  570.     tmp       = ffio_read_varlen(bc);

  571.     *back_ptr = nut->last_syncpoint_pos - 16 * ffio_read_varlen(bc);

  572.     if (*back_ptr < 0)

  573.         return AVERROR_INVALIDDATA;

  574. 

  575.     ff_nut_reset_ts(nut, nut->time_base[tmp % nut->time_base_count],

  576.                     tmp / nut->time_base_count);

  577. 

  578.     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {

  579.         av_log(s, AV_LOG_ERROR, "sync point checksum mismatch\n");

  580.         return AVERROR_INVALIDDATA;

  581.     }

  582. 

  583.     *ts = tmp / nut->time_base_count *

  584.           av_q2d(nut->time_base[tmp % nut->time_base_count]) * AV_TIME_BASE;

  585. 

  586.     if ((ret = ff_nut_add_sp(nut, nut->last_syncpoint_pos, *back_ptr, *ts)) < 0)

  587.         return ret;

  588. 

  589.     return 0;

  590. }

  591. 

  592. //FIXME calculate exactly, this is just a good approximation.

  593. static int64_t find_duration(NUTContext *nut, int64_t filesize)

  594. {

  595.     AVFormatContext *s = nut->avf;

  596.     int64_t duration = 0;

  597. 

  598.     ff_find_last_ts(s, -1, &duration, NULL, nut_read_timestamp);

  599. 

  600.     if(duration > 0)

  601.         s->duration_estimation_method = AVFMT_DURATION_FROM_PTS;

  602.     return duration;

  603. }

  604. 

  605. static int find_and_decode_index(NUTContext *nut)

  606. {

  607.     AVFormatContext *s = nut->avf;

  608.     AVIOContext *bc    = s->pb;

  609.     uint64_t tmp, end;

  610.     int i, j, syncpoint_count;

  611.     int64_t filesize = avio_size(bc);

  612.     int64_t *syncpoints;

  613.     uint64_t max_pts;

  614.     int8_t *has_keyframe;

  615.     int ret = AVERROR_INVALIDDATA;

  616. 

  617.     if(filesize <= 0)

  618.         return -1;

  619. 

  620.     avio_seek(bc, filesize - 12, SEEK_SET);

  621.     avio_seek(bc, filesize - avio_rb64(bc), SEEK_SET);

  622.     if (avio_rb64(bc) != INDEX_STARTCODE) {

  623.         av_log(s, AV_LOG_ERROR, "no index at the end\n");

  624. 

  625.         if(s->duration<=0)

  626.             s->duration = find_duration(nut, filesize);

  627.         return ret;

  628.     }

  629. 

  630.     end  = get_packetheader(nut, bc, 1, INDEX_STARTCODE);

  631.     end += avio_tell(bc);

  632. 

  633.     max_pts = ffio_read_varlen(bc);

  634.     s->duration = av_rescale_q(max_pts / nut->time_base_count,

  635.                                nut->time_base[max_pts % nut->time_base_count],

  636.                                AV_TIME_BASE_Q);

  637.     s->duration_estimation_method = AVFMT_DURATION_FROM_PTS;

  638. 

  639.     GET_V(syncpoint_count, tmp < INT_MAX / 8 && tmp > 0);

  640.     syncpoints   = av_malloc_array(syncpoint_count, sizeof(int64_t));

  641.     has_keyframe = av_malloc_array(syncpoint_count + 1, sizeof(int8_t));

  642.     if (!syncpoints || !has_keyframe) {

  643.         ret = AVERROR(ENOMEM);

  644.         goto fail;

  645.     }

  646.     for (i = 0; i < syncpoint_count; i++) {

  647.         syncpoints[i] = ffio_read_varlen(bc);

  648.         if (syncpoints[i] <= 0)

  649.             goto fail;

  650.         if (i)

  651.             syncpoints[i] += syncpoints[i - 1];

  652.     }

  653. 

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

  655.         int64_t last_pts = -1;

  656.         for (j = 0; j < syncpoint_count;) {

  657.             uint64_t x = ffio_read_varlen(bc);

  658.             int type   = x & 1;

  659.             int n      = j;

  660.             x >>= 1;

  661.             if (type) {

  662.                 int flag = x & 1;

  663.                 x >>= 1;

  664.                 if (n + x >= syncpoint_count + 1) {

  665.                     av_log(s, AV_LOG_ERROR, "index overflow A %d + %"PRIu64" >= %d\n", n, x, syncpoint_count + 1);

  666.                     goto fail;

  667.                 }

  668.                 while (x--)

  669.                     has_keyframe[n++] = flag;

  670.                 has_keyframe[n++] = !flag;

  671.             } else {

  672.                 while (x != 1) {

  673.                     if (n >= syncpoint_count + 1) {

  674.                         av_log(s, AV_LOG_ERROR, "index overflow B\n");

  675.                         goto fail;

  676.                     }

  677.                     has_keyframe[n++] = x & 1;

  678.                     x >>= 1;

  679.                 }

  680.             }

  681.             if (has_keyframe[0]) {

  682.                 av_log(s, AV_LOG_ERROR, "keyframe before first syncpoint in index\n");

  683.                 goto fail;

  684.             }

  685.             av_assert0(n <= syncpoint_count + 1);

  686.             for (; j < n && j < syncpoint_count; j++) {

  687.                 if (has_keyframe[j]) {

  688.                     uint64_t B, A = ffio_read_varlen(bc);

  689.                     if (!A) {

  690.                         A = ffio_read_varlen(bc);

  691.                         B = ffio_read_varlen(bc);

  692.                         // eor_pts[j][i] = last_pts + A + B

  693.                     } else

  694.                         B = 0;

  695.                     av_add_index_entry(s->streams[i], 16 * syncpoints[j - 1],

  696.                                        last_pts + A, 0, 0, AVINDEX_KEYFRAME);

  697.                     last_pts += A + B;

  698.                 }

  699.             }

  700.         }

  701.     }

  702. 

  703.     if (skip_reserved(bc, end) || ffio_get_checksum(bc)) {

  704.         av_log(s, AV_LOG_ERROR, "index checksum mismatch\n");

  705.         goto fail;

  706.     }

  707.     ret = 0;

  708. 

  709. fail:

  710.     av_free(syncpoints);

  711.     av_free(has_keyframe);

  712.     return ret;

  713. }

  714. 

  715. static int nut_read_header(AVFormatContext *s)

  716. {

  717.     NUTContext *nut = s->priv_data;

  718.     AVIOContext *bc = s->pb;

  719.     int64_t pos;

  720.     int initialized_stream_count;

  721. 

  722.     nut->avf = s;

  723. 

  724.     /* main header */

  725.     pos = 0;

  726.     do {

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

  728.         if (pos < 0 + 1) {

  729.             av_log(s, AV_LOG_ERROR, "No main startcode found.\n");

  730.             return AVERROR_INVALIDDATA;

  731.         }

  732.     } while (decode_main_header(nut) < 0);

  733. 

  734.     /* stream headers */

  735.     pos = 0;

  736.     for (initialized_stream_count = 0; initialized_stream_count < s->nb_streams;) {

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

  738.         if (pos < 0 + 1) {

  739.             av_log(s, AV_LOG_ERROR, "Not all stream headers found.\n");

  740.             return AVERROR_INVALIDDATA;

  741.         }

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

  743.             initialized_stream_count++;

  744.     }

  745. 

  746.     /* info headers */

  747.     pos = 0;

  748.     for (;;) {

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

  750.         pos = avio_tell(bc);

  751. 

  752.         if (startcode == 0) {

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

  754.             return AVERROR_INVALIDDATA;

  755.         } else if (startcode == SYNCPOINT_STARTCODE) {

  756.             nut->next_startcode = startcode;

  757.             break;

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

  759.             continue;

  760.         }

  761. 

  762.         decode_info_header(nut);

  763.     }

  764. 

  765.     s->data_offset = pos - 8;

  766. 

  767.     if (bc->seekable) {

  768.         int64_t orig_pos = avio_tell(bc);

  769.         find_and_decode_index(nut);

  770.         avio_seek(bc, orig_pos, SEEK_SET);

  771.     }

  772.     av_assert0(nut->next_startcode == SYNCPOINT_STARTCODE);

  773. 

  774.     ff_metadata_conv_ctx(s, NULL, ff_nut_metadata_conv);

  775. 

  776.     return 0;

  777. }

  778. 

  779. static int decode_frame_header(NUTContext *nut, int64_t *pts, int *stream_id,

  780.                                uint8_t *header_idx, int frame_code)

  781. {

  782.     AVFormatContext *s = nut->avf;

  783.     AVIOContext *bc    = s->pb;

  784.     StreamContext *stc;

  785.     int size, flags, size_mul, pts_delta, i, reserved_count;

  786.     uint64_t tmp;

  787. 

  788.     if (avio_tell(bc) > nut->last_syncpoint_pos + nut->max_distance) {

  789.         av_log(s, AV_LOG_ERROR,

  790.                "Last frame must have been damaged %"PRId64" > %"PRId64" + %d\n",

  791.                avio_tell(bc), nut->last_syncpoint_pos, nut->max_distance);

  792.         return AVERROR_INVALIDDATA;

  793.     }

  794. 

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

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

  797.     size           = nut->frame_code[frame_code].size_lsb;

  798.     *stream_id     = nut->frame_code[frame_code].stream_id;

  799.     pts_delta      = nut->frame_code[frame_code].pts_delta;

  800.     reserved_count = nut->frame_code[frame_code].reserved_count;

  801.     *header_idx    = nut->frame_code[frame_code].header_idx;

  802. 

  803.     if (flags & FLAG_INVALID)

  804.         return AVERROR_INVALIDDATA;

  805.     if (flags & FLAG_CODED)

  806.         flags ^= ffio_read_varlen(bc);

  807.     if (flags & FLAG_STREAM_ID) {

  808.         GET_V(*stream_id, tmp < s->nb_streams);

  809.     }

  810.     stc = &nut->stream[*stream_id];

  811.     if (flags & FLAG_CODED_PTS) {

  812.         int coded_pts = ffio_read_varlen(bc);

  813.         // FIXME check last_pts validity?

  814.         if (coded_pts < (1 << stc->msb_pts_shift)) {

  815.             *pts = ff_lsb2full(stc, coded_pts);

  816.         } else

  817.             *pts = coded_pts - (1LL << stc->msb_pts_shift);

  818.     } else

  819.         *pts = stc->last_pts + pts_delta;

  820.     if (flags & FLAG_SIZE_MSB)

  821.         size += size_mul * ffio_read_varlen(bc);

  822.     if (flags & FLAG_MATCH_TIME)

  823.         get_s(bc);

  824.     if (flags & FLAG_HEADER_IDX)

  825.         *header_idx = ffio_read_varlen(bc);

  826.     if (flags & FLAG_RESERVED)

  827.         reserved_count = ffio_read_varlen(bc);

  828.     for (i = 0; i < reserved_count; i++)

  829.         ffio_read_varlen(bc);

  830. 

  831.     if (*header_idx >= (unsigned)nut->header_count) {

  832.         av_log(s, AV_LOG_ERROR, "header_idx invalid\n");

  833.         return AVERROR_INVALIDDATA;

  834.     }

  835.     if (size > 4096)

  836.         *header_idx = 0;

  837.     size -= nut->header_len[*header_idx];

  838. 

  839.     if (flags & FLAG_CHECKSUM) {

  840.         avio_rb32(bc); // FIXME check this

  841.     } else if (size > 2 * nut->max_distance || FFABS(stc->last_pts - *pts) >

  842.                stc->max_pts_distance) {

  843.         av_log(s, AV_LOG_ERROR, "frame size > 2max_distance and no checksum\n");

  844.         return AVERROR_INVALIDDATA;

  845.     }

  846. 

  847.     stc->last_pts   = *pts;

  848.     stc->last_flags = flags;

  849. 

  850.     return size;

  851. }

  852. 

  853. static int decode_frame(NUTContext *nut, AVPacket *pkt, int frame_code)

  854. {

  855.     AVFormatContext *s = nut->avf;

  856.     AVIOContext *bc    = s->pb;

  857.     int size, stream_id, discard;

  858.     int64_t pts, last_IP_pts;

  859.     StreamContext *stc;

  860.     uint8_t header_idx;

  861. 

  862.     size = decode_frame_header(nut, &pts, &stream_id, &header_idx, frame_code);

  863.     if (size < 0)

  864.         return size;

  865. 

  866.     stc = &nut->stream[stream_id];

  867. 

  868.     if (stc->last_flags & FLAG_KEY)

  869.         stc->skip_until_key_frame = 0;

  870. 

  871.     discard     = s->streams[stream_id]->discard;

  872.     last_IP_pts = s->streams[stream_id]->last_IP_pts;

  873.     if ((discard >= AVDISCARD_NONKEY && !(stc->last_flags & FLAG_KEY)) ||

  874.         (discard >= AVDISCARD_BIDIR  && last_IP_pts != AV_NOPTS_VALUE &&

  875.          last_IP_pts > pts) ||

  876.         discard >= AVDISCARD_ALL ||

  877.         stc->skip_until_key_frame) {

  878.         avio_skip(bc, size);

  879.         return 1;

  880.     }

  881. 

  882.     if (av_new_packet(pkt, size + nut->header_len[header_idx]) < 0)

  883.         return AVERROR(ENOMEM);

  884.     memcpy(pkt->data, nut->header[header_idx], nut->header_len[header_idx]);

  885.     pkt->pos = avio_tell(bc); // FIXME

  886.     avio_read(bc, pkt->data + nut->header_len[header_idx], size);

  887. 

  888.     pkt->stream_index = stream_id;

  889.     if (stc->last_flags & FLAG_KEY)

  890.         pkt->flags |= AV_PKT_FLAG_KEY;

  891.     pkt->pts = pts;

  892. 

  893.     return 0;

  894. }

  895. 

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

  897. {

  898.     NUTContext *nut = s->priv_data;

  899.     AVIOContext *bc = s->pb;

  900.     int i, frame_code = 0, ret, skip;

  901.     int64_t ts, back_ptr;

  902. 

  903.     for (;;) {

  904.         int64_t pos  = avio_tell(bc);

  905.         uint64_t tmp = nut->next_startcode;

  906.         nut->next_startcode = 0;

  907. 

  908.         if (tmp) {

  909.             pos -= 8;

  910.         } else {

  911.             frame_code = avio_r8(bc);

  912.             if (url_feof(bc))

  913.                 return AVERROR_EOF;

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

  915.                 tmp = frame_code;

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

  917.                     tmp = (tmp << 8) + avio_r8(bc);

  918.             }

  919.         }

  920.         switch (tmp) {

  921.         case MAIN_STARTCODE:

  922.         case STREAM_STARTCODE:

  923.         case INDEX_STARTCODE:

  924.             skip = get_packetheader(nut, bc, 0, tmp);

  925.             avio_skip(bc, skip);

  926.             break;

  927.         case INFO_STARTCODE:

  928.             if (decode_info_header(nut) < 0)

  929.                 goto resync;

  930.             break;

  931.         case SYNCPOINT_STARTCODE:

  932.             if (decode_syncpoint(nut, &ts, &back_ptr) < 0)

  933.                 goto resync;

  934.             frame_code = avio_r8(bc);

  935.         case 0:

  936.             ret = decode_frame(nut, pkt, frame_code);

  937.             if (ret == 0)

  938.                 return 0;

  939.             else if (ret == 1) // OK but discard packet

  940.                 break;

  941.         default:

  942. resync:

  943.             av_log(s, AV_LOG_DEBUG, "syncing from %"PRId64"\n", pos);

  944.             tmp = find_any_startcode(bc, nut->last_syncpoint_pos + 1);

  945.             if (tmp == 0)

  946.                 return AVERROR_INVALIDDATA;

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

  948.             nut->next_startcode = tmp;

  949.         }

  950.     }

  951. }

  952. 

  953. static int64_t nut_read_timestamp(AVFormatContext *s, int stream_index,

  954.                                   int64_t *pos_arg, int64_t pos_limit)

  955. {

  956.     NUTContext *nut = s->priv_data;

  957.     AVIOContext *bc = s->pb;

  958.     int64_t pos, pts, back_ptr;

  959.     av_log(s, AV_LOG_DEBUG, "read_timestamp(X,%d,%"PRId64",%"PRId64")\n",

  960.            stream_index, *pos_arg, pos_limit);

  961. 

  962.     pos = *pos_arg;

  963.     do {

  964.         pos = find_startcode(bc, SYNCPOINT_STARTCODE, pos) + 1;

  965.         if (pos < 1) {

  966.             av_log(s, AV_LOG_ERROR, "read_timestamp failed.\n");

  967.             return AV_NOPTS_VALUE;

  968.         }

  969.     } while (decode_syncpoint(nut, &pts, &back_ptr) < 0);

  970.     *pos_arg = pos - 1;

  971.     av_assert0(nut->last_syncpoint_pos == *pos_arg);

  972. 

  973.     av_log(s, AV_LOG_DEBUG, "return %"PRId64" %"PRId64"\n", pts, back_ptr);

  974.     if (stream_index == -2)

  975.         return back_ptr;

  976.     av_assert0(stream_index == -1);

  977.     return pts;

  978. }

  979. 

  980. static int read_seek(AVFormatContext *s, int stream_index,

  981.                      int64_t pts, int flags)

  982. {

  983.     NUTContext *nut    = s->priv_data;

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

  985.     Syncpoint dummy    = { .ts = pts * av_q2d(st->time_base) * AV_TIME_BASE };

  986.     Syncpoint nopts_sp = { .ts = AV_NOPTS_VALUE, .back_ptr = AV_NOPTS_VALUE };

  987.     Syncpoint *sp, *next_node[2] = { &nopts_sp, &nopts_sp };

  988.     int64_t pos, pos2, ts;

  989.     int i;

  990. 

  991.     if (st->index_entries) {

  992.         int index = av_index_search_timestamp(st, pts, flags);

  993.         if (index < 0)

  994.             index = av_index_search_timestamp(st, pts, flags ^ AVSEEK_FLAG_BACKWARD);

  995.         if (index < 0)

  996.             return -1;

  997. 

  998.         pos2 = st->index_entries[index].pos;

  999.         ts   = st->index_entries[index].timestamp;

  1000.     } else {

  1001.         av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pts_cmp,

  1002.                      (void **) next_node);

  1003.         av_log(s, AV_LOG_DEBUG, "%"PRIu64"-%"PRIu64" %"PRId64"-%"PRId64"\n",

  1004.                next_node[0]->pos, next_node[1]->pos, next_node[0]->ts,

  1005.                next_node[1]->ts);

  1006.         pos = ff_gen_search(s, -1, dummy.ts, next_node[0]->pos,

  1007.                             next_node[1]->pos, next_node[1]->pos,

  1008.                             next_node[0]->ts, next_node[1]->ts,

  1009.                             AVSEEK_FLAG_BACKWARD, &ts, nut_read_timestamp);

  1010. 

  1011.         if (!(flags & AVSEEK_FLAG_BACKWARD)) {

  1012.             dummy.pos    = pos + 16;

  1013.             next_node[1] = &nopts_sp;

  1014.             av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,

  1015.                          (void **) next_node);

  1016.             pos2 = ff_gen_search(s, -2, dummy.pos, next_node[0]->pos,

  1017.                                  next_node[1]->pos, next_node[1]->pos,

  1018.                                  next_node[0]->back_ptr, next_node[1]->back_ptr,

  1019.                                  flags, &ts, nut_read_timestamp);

  1020.             if (pos2 >= 0)

  1021.                 pos = pos2;

  1022.             // FIXME dir but I think it does not matter

  1023.         }

  1024.         dummy.pos = pos;

  1025.         sp = av_tree_find(nut->syncpoints, &dummy, (void *) ff_nut_sp_pos_cmp,

  1026.                           NULL);

  1027. 

  1028.         av_assert0(sp);

  1029.         pos2 = sp->back_ptr - 15;

  1030.     }

  1031.     av_log(NULL, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos2);

  1032.     pos = find_startcode(s->pb, SYNCPOINT_STARTCODE, pos2);

  1033.     avio_seek(s->pb, pos, SEEK_SET);

  1034.     av_log(NULL, AV_LOG_DEBUG, "SP: %"PRId64"\n", pos);

  1035.     if (pos2 > pos || pos2 + 15 < pos)

  1036.         av_log(NULL, AV_LOG_ERROR, "no syncpoint at backptr pos\n");

  1037.     for (i = 0; i < s->nb_streams; i++)

  1038.         nut->stream[i].skip_until_key_frame = 1;

  1039. 

  1040.     return 0;

  1041. }

  1042. 

  1043. static int nut_read_close(AVFormatContext *s)

  1044. {

  1045.     NUTContext *nut = s->priv_data;

  1046.     int i;

  1047. 

  1048.     av_freep(&nut->time_base);

  1049.     av_freep(&nut->stream);

  1050.     ff_nut_free_sp(nut);

  1051.     for (i = 1; i < nut->header_count; i++)

  1052.         av_freep(&nut->header[i]);

  1053. 

  1054.     return 0;

  1055. }

  1056. 

  1057. AVInputFormat ff_nut_demuxer = {

  1058.     .name           = "nut",

  1059.     .long_name      = NULL_IF_CONFIG_SMALL("NUT"),

  1060.     .flags          = AVFMT_SEEK_TO_PTS,

  1061.     .priv_data_size = sizeof(NUTContext),

  1062.     .read_probe     = nut_probe,

  1063.     .read_header    = nut_read_header,

  1064.     .read_packet    = nut_read_packet,

  1065.     .read_close     = nut_read_close,

  1066.     .read_seek      = read_seek,

  1067.     .extensions     = "nut",

  1068.     .codec_tag      = ff_nut_codec_tags,

  1069. };