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FFmpeg/libavformat/ffmdec.c

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  1. /*

  2.  * FFM (ffserver live feed) demuxer

  3.  * Copyright (c) 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/intreadwrite.h"

  23. #include "avformat.h"

  24. #include "ffm.h"

  25. #if CONFIG_FFSERVER

  26. #include <unistd.h>

  27. 

  28. int64_t ffm_read_write_index(int fd)

  29. {

  30.     uint8_t buf[8];

  31. 

  32.     lseek(fd, 8, SEEK_SET);

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

  34.         return AVERROR(EIO);

  35.     return AV_RB64(buf);

  36. }

  37. 

  38. int ffm_write_write_index(int fd, int64_t pos)

  39. {

  40.     uint8_t buf[8];

  41.     int i;

  42. 

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

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

  45.     lseek(fd, 8, SEEK_SET);

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

  47.         return AVERROR(EIO);

  48.     return 8;

  49. }

  50. 

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

  52. {

  53.     FFMContext *ffm = s->priv_data;

  54.     ffm->write_index = pos;

  55.     ffm->file_size = file_size;

  56. }

  57. #endif // CONFIG_FFSERVER

  58. 

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

  60. {

  61.     FFMContext *ffm = s->priv_data;

  62.     int64_t pos, avail_size;

  63.     int len;

  64. 

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

  66.     if (size <= len)

  67.         return 1;

  68.     pos = url_ftell(s->pb);

  69.     if (!ffm->write_index) {

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

  71.             return AVERROR_EOF;

  72.         avail_size = ffm->file_size - pos;

  73.     } else {

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

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

  76.         return AVERROR(EAGAIN);

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

  78.         avail_size = ffm->write_index - pos;

  79.     } else {

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

  81.     }

  82.     }

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

  84.     if (size <= avail_size)

  85.         return 1;

  86.     else

  87.         return AVERROR(EAGAIN);

  88. }

  89. 

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

  91. {

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

  93.     while (state != PACKET_ID) {

  94.         if (url_feof(s->pb)) {

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

  96.             return -1;

  97.         }

  98.         state = (state << 8) | get_byte(s->pb);

  99.     }

  100.     return 0;

  101. }

  102. 

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

  104. static int ffm_read_data(AVFormatContext *s,

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

  106. {

  107.     FFMContext *ffm = s->priv_data;

  108.     ByteIOContext *pb = s->pb;

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

  110. 

  111.     size1 = size;

  112.     while (size > 0) {

  113.     redo:

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

  115.         if (len < 0)

  116.             return -1;

  117.         if (len > size)

  118.             len = size;

  119.         if (len == 0) {

  120.             if (url_ftell(pb) == ffm->file_size)

  121.                 url_fseek(pb, ffm->packet_size, SEEK_SET);

  122.     retry_read:

  123.             id = get_be16(pb); /* PACKET_ID */

  124.             if (id != PACKET_ID)

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

  126.                     return -1;

  127.             fill_size = get_be16(pb);

  128.             ffm->dts = get_be64(pb);

  129.             frame_offset = get_be16(pb);

  130.             get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);

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

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

  133.                 return -1;

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

  135.                handle it specifically */

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

  137.                 if (!frame_offset) {

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

  139.                     if (url_ftell(pb) >= ffm->packet_size * 3) {

  140.                         url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);

  141.                         goto retry_read;

  142.                     }

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

  144.                     return 0;

  145.                 }

  146.                 ffm->first_packet = 0;

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

  148.                     return -1;

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

  150.                 if (!header)

  151.                     break;

  152.             } else {

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

  154.             }

  155.             goto redo;

  156.         }

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

  158.         buf += len;

  159.         ffm->packet_ptr += len;

  160.         size -= len;

  161.         header = 0;

  162.     }

  163.     return size1 - size;

  164. }

  165. 

  166. //#define DEBUG_SEEK

  167. 

  168. /* ensure that acutal seeking happens between FFM_PACKET_SIZE

  169.    and file_size - FFM_PACKET_SIZE */

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

  171. {

  172.     FFMContext *ffm = s->priv_data;

  173.     ByteIOContext *pb = s->pb;

  174.     int64_t pos;

  175. 

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

  177.     pos = FFMAX(pos, FFM_PACKET_SIZE);

  178. #ifdef DEBUG_SEEK

  179.     av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);

  180. #endif

  181.     url_fseek(pb, pos, SEEK_SET);

  182. }

  183. 

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

  185. {

  186.     ByteIOContext *pb = s->pb;

  187.     int64_t dts;

  188. 

  189.     ffm_seek1(s, pos);

  190.     url_fskip(pb, 4);

  191.     dts = get_be64(pb);

  192. #ifdef DEBUG_SEEK

  193.     av_log(s, AV_LOG_DEBUG, "dts=%0.6f\n", dts / 1000000.0);

  194. #endif

  195.     return dts;

  196. }

  197. 

  198. static void adjust_write_index(AVFormatContext *s)

  199. {

  200.     FFMContext *ffm = s->priv_data;

  201.     ByteIOContext *pb = s->pb;

  202.     int64_t pts;

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

  204.     int64_t pos_min, pos_max;

  205.     int64_t pts_start;

  206.     int64_t ptr = url_ftell(pb);

  207. 

  208. 

  209.     pos_min = 0;

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

  211. 

  212.     pts_start = get_dts(s, pos_min);

  213. 

  214.     pts = get_dts(s, pos_max);

  215. 

  216.     if (pts - 100000 > pts_start)

  217.         goto end;

  218. 

  219.     ffm->write_index = FFM_PACKET_SIZE;

  220. 

  221.     pts_start = get_dts(s, pos_min);

  222. 

  223.     pts = get_dts(s, pos_max);

  224. 

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

  226.         while (1) {

  227.             int64_t newpos;

  228.             int64_t newpts;

  229. 

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

  231. 

  232.             if (newpos == pos_min)

  233.                 break;

  234. 

  235.             newpts = get_dts(s, newpos);

  236. 

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

  238.                 pos_max = newpos;

  239.                 pts = newpts;

  240.             } else {

  241.                 pos_min = newpos;

  242.             }

  243.         }

  244.         ffm->write_index += pos_max;

  245.     }

  246. 

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

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

  249. 

  250.  end:

  251.     url_fseek(pb, ptr, SEEK_SET);

  252. }

  253. 

  254. 

  255. static int ffm_close(AVFormatContext *s)

  256. {

  257.     int i;

  258. 

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

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

  261. 

  262.     return 0;

  263. }

  264. 

  265. 

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

  267. {

  268.     FFMContext *ffm = s->priv_data;

  269.     AVStream *st;

  270.     ByteIOContext *pb = s->pb;

  271.     AVCodecContext *codec;

  272.     int i, nb_streams;

  273.     uint32_t tag;

  274. 

  275.     /* header */

  276.     tag = get_le32(pb);

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

  278.         goto fail;

  279.     ffm->packet_size = get_be32(pb);

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

  281.         goto fail;

  282.     ffm->write_index = get_be64(pb);

  283.     /* get also filesize */

  284.     if (!url_is_streamed(pb)) {

  285.         ffm->file_size = url_fsize(pb);

  286.         if (ffm->write_index)

  287.             adjust_write_index(s);

  288.     } else {

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

  290.     }

  291. 

  292.     nb_streams = get_be32(pb);

  293.     get_be32(pb); /* total bitrate */

  294.     /* read each stream */

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

  296.         char rc_eq_buf[128];

  297. 

  298.         st = av_new_stream(s, 0);

  299.         if (!st)

  300.             goto fail;

  301. 

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

  303. 

  304.         codec = st->codec;

  305.         /* generic info */

  306.         codec->codec_id = get_be32(pb);

  307.         codec->codec_type = get_byte(pb); /* codec_type */

  308.         codec->bit_rate = get_be32(pb);

  309.         st->quality = get_be32(pb);

  310.         codec->flags = get_be32(pb);

  311.         codec->flags2 = get_be32(pb);

  312.         codec->debug = get_be32(pb);

  313.         /* specific info */

  314.         switch(codec->codec_type) {

  315.         case AVMEDIA_TYPE_VIDEO:

  316.             codec->time_base.num = get_be32(pb);

  317.             codec->time_base.den = get_be32(pb);

  318.             codec->width = get_be16(pb);

  319.             codec->height = get_be16(pb);

  320.             codec->gop_size = get_be16(pb);

  321.             codec->pix_fmt = get_be32(pb);

  322.             codec->qmin = get_byte(pb);

  323.             codec->qmax = get_byte(pb);

  324.             codec->max_qdiff = get_byte(pb);

  325.             codec->qcompress = get_be16(pb) / 10000.0;

  326.             codec->qblur = get_be16(pb) / 10000.0;

  327.             codec->bit_rate_tolerance = get_be32(pb);

  328.             codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));

  329.             codec->rc_max_rate = get_be32(pb);

  330.             codec->rc_min_rate = get_be32(pb);

  331.             codec->rc_buffer_size = get_be32(pb);

  332.             codec->i_quant_factor = av_int2dbl(get_be64(pb));

  333.             codec->b_quant_factor = av_int2dbl(get_be64(pb));

  334.             codec->i_quant_offset = av_int2dbl(get_be64(pb));

  335.             codec->b_quant_offset = av_int2dbl(get_be64(pb));

  336.             codec->dct_algo = get_be32(pb);

  337.             codec->strict_std_compliance = get_be32(pb);

  338.             codec->max_b_frames = get_be32(pb);

  339.             codec->luma_elim_threshold = get_be32(pb);

  340.             codec->chroma_elim_threshold = get_be32(pb);

  341.             codec->mpeg_quant = get_be32(pb);

  342.             codec->intra_dc_precision = get_be32(pb);

  343.             codec->me_method = get_be32(pb);

  344.             codec->mb_decision = get_be32(pb);

  345.             codec->nsse_weight = get_be32(pb);

  346.             codec->frame_skip_cmp = get_be32(pb);

  347.             codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));

  348.             codec->codec_tag = get_be32(pb);

  349.             codec->thread_count = get_byte(pb);

  350.             codec->coder_type = get_be32(pb);

  351.             codec->me_cmp = get_be32(pb);

  352.             codec->partitions = get_be32(pb);

  353.             codec->me_subpel_quality = get_be32(pb);

  354.             codec->me_range = get_be32(pb);

  355.             codec->keyint_min = get_be32(pb);

  356.             codec->scenechange_threshold = get_be32(pb);

  357.             codec->b_frame_strategy = get_be32(pb);

  358.             codec->qcompress = av_int2dbl(get_be64(pb));

  359.             codec->qblur = av_int2dbl(get_be64(pb));

  360.             codec->max_qdiff = get_be32(pb);

  361.             codec->refs = get_be32(pb);

  362.             codec->directpred = get_be32(pb);

  363.             break;

  364.         case AVMEDIA_TYPE_AUDIO:

  365.             codec->sample_rate = get_be32(pb);

  366.             codec->channels = get_le16(pb);

  367.             codec->frame_size = get_le16(pb);

  368.             codec->sample_fmt = (int16_t) get_le16(pb);

  369.             break;

  370.         default:

  371.             goto fail;

  372.         }

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

  374.             codec->extradata_size = get_be32(pb);

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

  376.             if (!codec->extradata)

  377.                 return AVERROR(ENOMEM);

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

  379.         }

  380.     }

  381. 

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

  383.     while ((url_ftell(pb) % ffm->packet_size) != 0)

  384.         get_byte(pb);

  385. 

  386.     /* init packet demux */

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

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

  389.     ffm->frame_offset = 0;

  390.     ffm->dts = 0;

  391.     ffm->read_state = READ_HEADER;

  392.     ffm->first_packet = 1;

  393.     return 0;

  394.  fail:

  395.     ffm_close(s);

  396.     return -1;

  397. }

  398. 

  399. /* return < 0 if eof */

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

  401. {

  402.     int size;

  403.     FFMContext *ffm = s->priv_data;

  404.     int duration, ret;

  405. 

  406.     switch(ffm->read_state) {

  407.     case READ_HEADER:

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

  409.             return ret;

  410. 

  411.         dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",

  412.                url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);

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

  414.             FRAME_HEADER_SIZE)

  415.             return -1;

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

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

  418.                 return -1;

  419. #if 0

  420.         av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);

  421. #endif

  422.         ffm->read_state = READ_DATA;

  423.         /* fall thru */

  424.     case READ_DATA:

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

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

  427.             return ret;

  428. 

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

  430. 

  431.         av_new_packet(pkt, size);

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

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

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

  435.             av_free_packet(pkt);

  436.             ffm->read_state = READ_HEADER;

  437.             return -1;

  438.         }

  439.         pkt->pos = url_ftell(s->pb);

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

  441.             pkt->flags |= AV_PKT_FLAG_KEY;

  442. 

  443.         ffm->read_state = READ_HEADER;

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

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

  446.             av_free_packet(pkt);

  447.             return -1;

  448.         }

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

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

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

  452.         else

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

  454.         pkt->duration = duration;

  455.         break;

  456.     }

  457.     return 0;

  458. }

  459. 

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

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

  462.    approximative */

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

  464. {

  465.     FFMContext *ffm = s->priv_data;

  466.     int64_t pos_min, pos_max, pos;

  467.     int64_t pts_min, pts_max, pts;

  468.     double pos1;

  469. 

  470. #ifdef DEBUG_SEEK

  471.     av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);

  472. #endif

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

  474.        dichotomy in typical cases) */

  475.     pos_min = FFM_PACKET_SIZE;

  476.     pos_max = ffm->file_size - FFM_PACKET_SIZE;

  477.     while (pos_min <= pos_max) {

  478.         pts_min = get_dts(s, pos_min);

  479.         pts_max = get_dts(s, pos_max);

  480.         /* linear interpolation */

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

  482.             (double)(pts_max - pts_min);

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

  484.         if (pos <= pos_min)

  485.             pos = pos_min;

  486.         else if (pos >= pos_max)

  487.             pos = pos_max;

  488.         pts = get_dts(s, pos);

  489.         /* check if we are lucky */

  490.         if (pts == wanted_pts) {

  491.             goto found;

  492.         } else if (pts > wanted_pts) {

  493.             pos_max = pos - FFM_PACKET_SIZE;

  494.         } else {

  495.             pos_min = pos + FFM_PACKET_SIZE;

  496.         }

  497.     }

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

  499. 

  500.  found:

  501.     ffm_seek1(s, pos);

  502. 

  503.     /* reset read state */

  504.     ffm->read_state = READ_HEADER;

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

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

  507.     ffm->first_packet = 1;

  508. 

  509.     return 0;

  510. }

  511. 

  512. static int ffm_probe(AVProbeData *p)

  513. {

  514.     if (

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

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

  517.         return AVPROBE_SCORE_MAX + 1;

  518.     return 0;

  519. }

  520. 

  521. AVInputFormat ffm_demuxer = {

  522.     "ffm",

  523.     NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),

  524.     sizeof(FFMContext),

  525.     ffm_probe,

  526.     ffm_read_header,

  527.     ffm_read_packet,

  528.     ffm_close,

  529.     ffm_seek,

  530. };