Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * Adobe Filmstrip demuxer
  3.  * Copyright (c) 2010 Peter Ross
  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. /**
  23.  * @file
  24.  * Adobe Filmstrip demuxer
  25.  */
  26.  
  27. #include "libavutil/intreadwrite.h"
  28. #include "avformat.h"
  29. #include "internal.h"
  30.  
  31. #define RAND_TAG MKBETAG('R','a','n','d')
  32.  
  33. typedef struct {
  34.     int leading;
  35. } FilmstripDemuxContext;
  36.  
  37. static int read_header(AVFormatContext *s)
  38. {
  39.     FilmstripDemuxContext *film = s->priv_data;
  40.     AVIOContext *pb = s->pb;
  41.     AVStream *st;
  42.  
  43.     if (!s->pb->seekable)
  44.         return AVERROR(EIO);
  45.  
  46.     avio_seek(pb, avio_size(pb) - 36, SEEK_SET);
  47.     if (avio_rb32(pb) != RAND_TAG) {
  48.         av_log(s, AV_LOG_ERROR, "magic number not found\n");
  49.         return AVERROR_INVALIDDATA;
  50.     }
  51.  
  52.     st = avformat_new_stream(s, NULL);
  53.     if (!st)
  54.         return AVERROR(ENOMEM);
  55.  
  56.     st->nb_frames = avio_rb32(pb);
  57.     if (avio_rb16(pb) != 0) {
  58.         avpriv_request_sample(s, "Unsupported packing method");
  59.         return AVERROR_PATCHWELCOME;
  60.     }
  61.  
  62.     avio_skip(pb, 2);
  63.     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
  64.     st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
  65.     st->codec->pix_fmt    = AV_PIX_FMT_RGBA;
  66.     st->codec->codec_tag  = 0; /* no fourcc */
  67.     st->codec->width      = avio_rb16(pb);
  68.     st->codec->height     = avio_rb16(pb);
  69.     film->leading         = avio_rb16(pb);
  70.     avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
  71.  
  72.     avio_seek(pb, 0, SEEK_SET);
  73.  
  74.     return 0;
  75. }
  76.  
  77. static int read_packet(AVFormatContext *s,
  78.                        AVPacket *pkt)
  79. {
  80.     FilmstripDemuxContext *film = s->priv_data;
  81.     AVStream *st = s->streams[0];
  82.  
  83.     if (url_feof(s->pb))
  84.         return AVERROR(EIO);
  85.     pkt->dts = avio_tell(s->pb) / (st->codec->width * (st->codec->height + film->leading) * 4);
  86.     pkt->size = av_get_packet(s->pb, pkt, st->codec->width * st->codec->height * 4);
  87.     avio_skip(s->pb, st->codec->width * film->leading * 4);
  88.     if (pkt->size < 0)
  89.         return pkt->size;
  90.     pkt->flags |= AV_PKT_FLAG_KEY;
  91.     return 0;
  92. }
  93.  
  94. static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
  95. {
  96.     AVStream *st = s->streams[stream_index];
  97.     if (avio_seek(s->pb, FFMAX(timestamp, 0) * st->codec->width * st->codec->height * 4, SEEK_SET) < 0)
  98.         return -1;
  99.     return 0;
  100. }
  101.  
  102. AVInputFormat ff_filmstrip_demuxer = {
  103.     .name           = "filmstrip",
  104.     .long_name      = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
  105.     .priv_data_size = sizeof(FilmstripDemuxContext),
  106.     .read_header    = read_header,
  107.     .read_packet    = read_packet,
  108.     .read_seek      = read_seek,
  109.     .extensions     = "flm",
  110. };
  111.