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FFmpeg/libavformat/ffmdec.c

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  1. /*

  2.  * FFM (avserver live feed) demuxer

  3.  * Copyright (c) 2001 Fabrice Bellard

  4.  *

  5.  * This file is part of Libav.

  6.  *

  7.  * Libav 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.  * Libav 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 Libav; 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/intreadwrite.h"

  23. #include "libavutil/intfloat_readwrite.h"

  24. #include "avformat.h"

  25. #include "ffm.h"

  26. #if CONFIG_AVSERVER

  27. #include <unistd.h>

  28. 

  29. int64_t ffm_read_write_index(int fd)

  30. {

  31.     uint8_t buf[8];

  32. 

  33.     lseek(fd, 8, SEEK_SET);

  34.     if (read(fd, buf, 8) != 8)

  35.         return AVERROR(EIO);

  36.     return AV_RB64(buf);

  37. }

  38. 

  39. int ffm_write_write_index(int fd, int64_t pos)

  40. {

  41.     uint8_t buf[8];

  42.     int i;

  43. 

  44.     for(i=0;i<8;i++)

  45.         buf[i] = (pos >> (56 - i * 8)) & 0xff;

  46.     lseek(fd, 8, SEEK_SET);

  47.     if (write(fd, buf, 8) != 8)

  48.         return AVERROR(EIO);

  49.     return 8;

  50. }

  51. 

  52. void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)

  53. {

  54.     FFMContext *ffm = s->priv_data;

  55.     ffm->write_index = pos;

  56.     ffm->file_size = file_size;

  57. }

  58. #endif // CONFIG_AVSERVER

  59. 

  60. static int ffm_is_avail_data(AVFormatContext *s, int size)

  61. {

  62.     FFMContext *ffm = s->priv_data;

  63.     int64_t pos, avail_size;

  64.     int len;

  65. 

  66.     len = ffm->packet_end - ffm->packet_ptr;

  67.     if (size <= len)

  68.         return 1;

  69.     pos = avio_tell(s->pb);

  70.     if (!ffm->write_index) {

  71.         if (pos == ffm->file_size)

  72.             return AVERROR_EOF;

  73.         avail_size = ffm->file_size - pos;

  74.     } else {

  75.     if (pos == ffm->write_index) {

  76.         /* exactly at the end of stream */

  77.         return AVERROR(EAGAIN);

  78.     } else if (pos < ffm->write_index) {

  79.         avail_size = ffm->write_index - pos;

  80.     } else {

  81.         avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);

  82.     }

  83.     }

  84.     avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;

  85.     if (size <= avail_size)

  86.         return 1;

  87.     else

  88.         return AVERROR(EAGAIN);

  89. }

  90. 

  91. static int ffm_resync(AVFormatContext *s, int state)

  92. {

  93.     av_log(s, AV_LOG_ERROR, "resyncing\n");

  94.     while (state != PACKET_ID) {

  95.         if (s->pb->eof_reached) {

  96.             av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");

  97.             return -1;

  98.         }

  99.         state = (state << 8) | avio_r8(s->pb);

  100.     }

  101.     return 0;

  102. }

  103. 

  104. /* first is true if we read the frame header */

  105. static int ffm_read_data(AVFormatContext *s,

  106.                          uint8_t *buf, int size, int header)

  107. {

  108.     FFMContext *ffm = s->priv_data;

  109.     AVIOContext *pb = s->pb;

  110.     int len, fill_size, size1, frame_offset, id;

  111. 

  112.     size1 = size;

  113.     while (size > 0) {

  114.     redo:

  115.         len = ffm->packet_end - ffm->packet_ptr;

  116.         if (len < 0)

  117.             return -1;

  118.         if (len > size)

  119.             len = size;

  120.         if (len == 0) {

  121.             if (avio_tell(pb) == ffm->file_size)

  122.                 avio_seek(pb, ffm->packet_size, SEEK_SET);

  123.     retry_read:

  124.             id = avio_rb16(pb); /* PACKET_ID */

  125.             if (id != PACKET_ID)

  126.                 if (ffm_resync(s, id) < 0)

  127.                     return -1;

  128.             fill_size = avio_rb16(pb);

  129.             ffm->dts = avio_rb64(pb);

  130.             frame_offset = avio_rb16(pb);

  131.             avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);

  132.             ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);

  133.             if (ffm->packet_end < ffm->packet || frame_offset < 0)

  134.                 return -1;

  135.             /* if first packet or resynchronization packet, we must

  136.                handle it specifically */

  137.             if (ffm->first_packet || (frame_offset & 0x8000)) {

  138.                 if (!frame_offset) {

  139.                     /* This packet has no frame headers in it */

  140.                     if (avio_tell(pb) >= ffm->packet_size * 3) {

  141.                         avio_seek(pb, -ffm->packet_size * 2, SEEK_CUR);

  142.                         goto retry_read;

  143.                     }

  144.                     /* This is bad, we cannot find a valid frame header */

  145.                     return 0;

  146.                 }

  147.                 ffm->first_packet = 0;

  148.                 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)

  149.                     return -1;

  150.                 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;

  151.                 if (!header)

  152.                     break;

  153.             } else {

  154.                 ffm->packet_ptr = ffm->packet;

  155.             }

  156.             goto redo;

  157.         }

  158.         memcpy(buf, ffm->packet_ptr, len);

  159.         buf += len;

  160.         ffm->packet_ptr += len;

  161.         size -= len;

  162.         header = 0;

  163.     }

  164.     return size1 - size;

  165. }

  166. 

  167. /* ensure that acutal seeking happens between FFM_PACKET_SIZE

  168.    and file_size - FFM_PACKET_SIZE */

  169. static void ffm_seek1(AVFormatContext *s, int64_t pos1)

  170. {

  171.     FFMContext *ffm = s->priv_data;

  172.     AVIOContext *pb = s->pb;

  173.     int64_t pos;

  174. 

  175.     pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);

  176.     pos = FFMAX(pos, FFM_PACKET_SIZE);

  177.     av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);

  178.     avio_seek(pb, pos, SEEK_SET);

  179. }

  180. 

  181. static int64_t get_dts(AVFormatContext *s, int64_t pos)

  182. {

  183.     AVIOContext *pb = s->pb;

  184.     int64_t dts;

  185. 

  186.     ffm_seek1(s, pos);

  187.     avio_skip(pb, 4);

  188.     dts = avio_rb64(pb);

  189.     av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);

  190.     return dts;

  191. }

  192. 

  193. static void adjust_write_index(AVFormatContext *s)

  194. {

  195.     FFMContext *ffm = s->priv_data;

  196.     AVIOContext *pb = s->pb;

  197.     int64_t pts;

  198.     //int64_t orig_write_index = ffm->write_index;

  199.     int64_t pos_min, pos_max;

  200.     int64_t pts_start;

  201.     int64_t ptr = avio_tell(pb);

  202. 

  203. 

  204.     pos_min = 0;

  205.     pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;

  206. 

  207.     pts_start = get_dts(s, pos_min);

  208. 

  209.     pts = get_dts(s, pos_max);

  210. 

  211.     if (pts - 100000 > pts_start)

  212.         goto end;

  213. 

  214.     ffm->write_index = FFM_PACKET_SIZE;

  215. 

  216.     pts_start = get_dts(s, pos_min);

  217. 

  218.     pts = get_dts(s, pos_max);

  219. 

  220.     if (pts - 100000 <= pts_start) {

  221.         while (1) {

  222.             int64_t newpos;

  223.             int64_t newpts;

  224. 

  225.             newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;

  226. 

  227.             if (newpos == pos_min)

  228.                 break;

  229. 

  230.             newpts = get_dts(s, newpos);

  231. 

  232.             if (newpts - 100000 <= pts) {

  233.                 pos_max = newpos;

  234.                 pts = newpts;

  235.             } else {

  236.                 pos_min = newpos;

  237.             }

  238.         }

  239.         ffm->write_index += pos_max;

  240.     }

  241. 

  242.     //printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);

  243.     //printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );

  244. 

  245.  end:

  246.     avio_seek(pb, ptr, SEEK_SET);

  247. }

  248. 

  249. 

  250. static int ffm_close(AVFormatContext *s)

  251. {

  252.     int i;

  253. 

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

  255.         av_freep(&s->streams[i]->codec->rc_eq);

  256. 

  257.     return 0;

  258. }

  259. 

  260. 

  261. static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)

  262. {

  263.     FFMContext *ffm = s->priv_data;

  264.     AVStream *st;

  265.     AVIOContext *pb = s->pb;

  266.     AVCodecContext *codec;

  267.     int i, nb_streams;

  268.     uint32_t tag;

  269. 

  270.     /* header */

  271.     tag = avio_rl32(pb);

  272.     if (tag != MKTAG('F', 'F', 'M', '1'))

  273.         goto fail;

  274.     ffm->packet_size = avio_rb32(pb);

  275.     if (ffm->packet_size != FFM_PACKET_SIZE)

  276.         goto fail;

  277.     ffm->write_index = avio_rb64(pb);

  278.     /* get also filesize */

  279.     if (pb->seekable) {

  280.         ffm->file_size = avio_size(pb);

  281.         if (ffm->write_index)

  282.             adjust_write_index(s);

  283.     } else {

  284.         ffm->file_size = (UINT64_C(1) << 63) - 1;

  285.     }

  286. 

  287.     nb_streams = avio_rb32(pb);

  288.     avio_rb32(pb); /* total bitrate */

  289.     /* read each stream */

  290.     for(i=0;i<nb_streams;i++) {

  291.         char rc_eq_buf[128];

  292. 

  293.         st = av_new_stream(s, 0);

  294.         if (!st)

  295.             goto fail;

  296. 

  297.         av_set_pts_info(st, 64, 1, 1000000);

  298. 

  299.         codec = st->codec;

  300.         /* generic info */

  301.         codec->codec_id = avio_rb32(pb);

  302.         codec->codec_type = avio_r8(pb); /* codec_type */

  303.         codec->bit_rate = avio_rb32(pb);

  304.         codec->flags = avio_rb32(pb);

  305.         codec->flags2 = avio_rb32(pb);

  306.         codec->debug = avio_rb32(pb);

  307.         /* specific info */

  308.         switch(codec->codec_type) {

  309.         case AVMEDIA_TYPE_VIDEO:

  310.             codec->time_base.num = avio_rb32(pb);

  311.             codec->time_base.den = avio_rb32(pb);

  312.             codec->width = avio_rb16(pb);

  313.             codec->height = avio_rb16(pb);

  314.             codec->gop_size = avio_rb16(pb);

  315.             codec->pix_fmt = avio_rb32(pb);

  316.             codec->qmin = avio_r8(pb);

  317.             codec->qmax = avio_r8(pb);

  318.             codec->max_qdiff = avio_r8(pb);

  319.             codec->qcompress = avio_rb16(pb) / 10000.0;

  320.             codec->qblur = avio_rb16(pb) / 10000.0;

  321.             codec->bit_rate_tolerance = avio_rb32(pb);

  322.             avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));

  323.             codec->rc_eq = av_strdup(rc_eq_buf);

  324.             codec->rc_max_rate = avio_rb32(pb);

  325.             codec->rc_min_rate = avio_rb32(pb);

  326.             codec->rc_buffer_size = avio_rb32(pb);

  327.             codec->i_quant_factor = av_int2dbl(avio_rb64(pb));

  328.             codec->b_quant_factor = av_int2dbl(avio_rb64(pb));

  329.             codec->i_quant_offset = av_int2dbl(avio_rb64(pb));

  330.             codec->b_quant_offset = av_int2dbl(avio_rb64(pb));

  331.             codec->dct_algo = avio_rb32(pb);

  332.             codec->strict_std_compliance = avio_rb32(pb);

  333.             codec->max_b_frames = avio_rb32(pb);

  334.             codec->luma_elim_threshold = avio_rb32(pb);

  335.             codec->chroma_elim_threshold = avio_rb32(pb);

  336.             codec->mpeg_quant = avio_rb32(pb);

  337.             codec->intra_dc_precision = avio_rb32(pb);

  338.             codec->me_method = avio_rb32(pb);

  339.             codec->mb_decision = avio_rb32(pb);

  340.             codec->nsse_weight = avio_rb32(pb);

  341.             codec->frame_skip_cmp = avio_rb32(pb);

  342.             codec->rc_buffer_aggressivity = av_int2dbl(avio_rb64(pb));

  343.             codec->codec_tag = avio_rb32(pb);

  344.             codec->thread_count = avio_r8(pb);

  345.             codec->coder_type = avio_rb32(pb);

  346.             codec->me_cmp = avio_rb32(pb);

  347.             codec->me_subpel_quality = avio_rb32(pb);

  348.             codec->me_range = avio_rb32(pb);

  349.             codec->keyint_min = avio_rb32(pb);

  350.             codec->scenechange_threshold = avio_rb32(pb);

  351.             codec->b_frame_strategy = avio_rb32(pb);

  352.             codec->qcompress = av_int2dbl(avio_rb64(pb));

  353.             codec->qblur = av_int2dbl(avio_rb64(pb));

  354.             codec->max_qdiff = avio_rb32(pb);

  355.             codec->refs = avio_rb32(pb);

  356.             break;

  357.         case AVMEDIA_TYPE_AUDIO:

  358.             codec->sample_rate = avio_rb32(pb);

  359.             codec->channels = avio_rl16(pb);

  360.             codec->frame_size = avio_rl16(pb);

  361.             codec->sample_fmt = (int16_t) avio_rl16(pb);

  362.             break;

  363.         default:

  364.             goto fail;

  365.         }

  366.         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {

  367.             codec->extradata_size = avio_rb32(pb);

  368.             codec->extradata = av_malloc(codec->extradata_size);

  369.             if (!codec->extradata)

  370.                 return AVERROR(ENOMEM);

  371.             avio_read(pb, codec->extradata, codec->extradata_size);

  372.         }

  373.     }

  374. 

  375.     /* get until end of block reached */

  376.     while ((avio_tell(pb) % ffm->packet_size) != 0)

  377.         avio_r8(pb);

  378. 

  379.     /* init packet demux */

  380.     ffm->packet_ptr = ffm->packet;

  381.     ffm->packet_end = ffm->packet;

  382.     ffm->frame_offset = 0;

  383.     ffm->dts = 0;

  384.     ffm->read_state = READ_HEADER;

  385.     ffm->first_packet = 1;

  386.     return 0;

  387.  fail:

  388.     ffm_close(s);

  389.     return -1;

  390. }

  391. 

  392. /* return < 0 if eof */

  393. static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)

  394. {

  395.     int size;

  396.     FFMContext *ffm = s->priv_data;

  397.     int duration, ret;

  398. 

  399.     switch(ffm->read_state) {

  400.     case READ_HEADER:

  401.         if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)

  402.             return ret;

  403. 

  404.         av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",

  405.                avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);

  406.         if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=

  407.             FRAME_HEADER_SIZE)

  408.             return -1;

  409.         if (ffm->header[1] & FLAG_DTS)

  410.             if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)

  411.                 return -1;

  412.         ffm->read_state = READ_DATA;

  413.         /* fall thru */

  414.     case READ_DATA:

  415.         size = AV_RB24(ffm->header + 2);

  416.         if ((ret = ffm_is_avail_data(s, size)) < 0)

  417.             return ret;

  418. 

  419.         duration = AV_RB24(ffm->header + 5);

  420. 

  421.         av_new_packet(pkt, size);

  422.         pkt->stream_index = ffm->header[0];

  423.         if ((unsigned)pkt->stream_index >= s->nb_streams) {

  424.             av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);

  425.             av_free_packet(pkt);

  426.             ffm->read_state = READ_HEADER;

  427.             return -1;

  428.         }

  429.         pkt->pos = avio_tell(s->pb);

  430.         if (ffm->header[1] & FLAG_KEY_FRAME)

  431.             pkt->flags |= AV_PKT_FLAG_KEY;

  432. 

  433.         ffm->read_state = READ_HEADER;

  434.         if (ffm_read_data(s, pkt->data, size, 0) != size) {

  435.             /* bad case: desynchronized packet. we cancel all the packet loading */

  436.             av_free_packet(pkt);

  437.             return -1;

  438.         }

  439.         pkt->pts = AV_RB64(ffm->header+8);

  440.         if (ffm->header[1] & FLAG_DTS)

  441.             pkt->dts = pkt->pts - AV_RB32(ffm->header+16);

  442.         else

  443.             pkt->dts = pkt->pts;

  444.         pkt->duration = duration;

  445.         break;

  446.     }

  447.     return 0;

  448. }

  449. 

  450. /* seek to a given time in the file. The file read pointer is

  451.    positioned at or before pts. XXX: the following code is quite

  452.    approximative */

  453. static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)

  454. {

  455.     FFMContext *ffm = s->priv_data;

  456.     int64_t pos_min, pos_max, pos;

  457.     int64_t pts_min, pts_max, pts;

  458.     double pos1;

  459. 

  460.     av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);

  461.     /* find the position using linear interpolation (better than

  462.        dichotomy in typical cases) */

  463.     pos_min = FFM_PACKET_SIZE;

  464.     pos_max = ffm->file_size - FFM_PACKET_SIZE;

  465.     while (pos_min <= pos_max) {

  466.         pts_min = get_dts(s, pos_min);

  467.         pts_max = get_dts(s, pos_max);

  468.         /* linear interpolation */

  469.         pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /

  470.             (double)(pts_max - pts_min);

  471.         pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;

  472.         if (pos <= pos_min)

  473.             pos = pos_min;

  474.         else if (pos >= pos_max)

  475.             pos = pos_max;

  476.         pts = get_dts(s, pos);

  477.         /* check if we are lucky */

  478.         if (pts == wanted_pts) {

  479.             goto found;

  480.         } else if (pts > wanted_pts) {

  481.             pos_max = pos - FFM_PACKET_SIZE;

  482.         } else {

  483.             pos_min = pos + FFM_PACKET_SIZE;

  484.         }

  485.     }

  486.     pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;

  487. 

  488.  found:

  489.     ffm_seek1(s, pos);

  490. 

  491.     /* reset read state */

  492.     ffm->read_state = READ_HEADER;

  493.     ffm->packet_ptr = ffm->packet;

  494.     ffm->packet_end = ffm->packet;

  495.     ffm->first_packet = 1;

  496. 

  497.     return 0;

  498. }

  499. 

  500. static int ffm_probe(AVProbeData *p)

  501. {

  502.     if (

  503.         p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&

  504.         p->buf[3] == '1')

  505.         return AVPROBE_SCORE_MAX + 1;

  506.     return 0;

  507. }

  508. 

  509. AVInputFormat ff_ffm_demuxer = {

  510.     .name           = "ffm",

  511.     .long_name      = NULL_IF_CONFIG_SMALL("FFM (AVserver live feed) format"),

  512.     .priv_data_size = sizeof(FFMContext),

  513.     .read_probe     = ffm_probe,

  514.     .read_header    = ffm_read_header,

  515.     .read_packet    = ffm_read_packet,

  516.     .read_close     = ffm_close,

  517.     .read_seek      = ffm_seek,

  518. };