libavformat/filmstripenc.c

   1 /*
   2  * Adobe Filmstrip muxer
   3  * Copyright (c) 2010 Peter Ross
   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 /**
  23  * @file
  24  * Adobe Filmstrip muxer
  25  */
  26
  27 #include "libavutil/intreadwrite.h"
  28 #include "avformat.h"
  29
  30 #define RAND_TAG MKBETAG('R','a','n','d')
  31
  32 typedef struct {
  33     int nb_frames;
  34 } FilmstripMuxContext;
  35
  36 static int write_header(AVFormatContext *s)
  37 {
  38     if (s->streams[0]->codec->pix_fmt != AV_PIX_FMT_RGBA) {
  39         av_log(s, AV_LOG_ERROR, "only AV_PIX_FMT_RGBA is supported\n");
  40         return AVERROR_INVALIDDATA;
  41     }
  42     return 0;
  43 }
  44
  45 static int write_packet(AVFormatContext *s, AVPacket *pkt)
  46 {
  47     FilmstripMuxContext *film = s->priv_data;
  48     avio_write(s->pb, pkt->data, pkt->size);
  49     film->nb_frames++;
  50     return 0;
  51 }
  52
  53 static int write_trailer(AVFormatContext *s)
  54 {
  55     FilmstripMuxContext *film = s->priv_data;
  56     AVIOContext *pb = s->pb;
  57     AVStream *st = s->streams[0];
  58     int i;
  59
  60     avio_wb32(pb, RAND_TAG);
  61     avio_wb32(pb, film->nb_frames);
  62     avio_wb16(pb, 0);  // packing method
  63     avio_wb16(pb, 0);  // reserved
  64     avio_wb16(pb, st->codec->width);
  65     avio_wb16(pb, st->codec->height);
  66     avio_wb16(pb, 0);  // leading
  67     avio_wb16(pb, 1/av_q2d(st->codec->time_base));
  68     for (i = 0; i < 16; i++)
  69         avio_w8(pb, 0x00);  // reserved
  70
  71     return 0;
  72 }
  73
  74 AVOutputFormat ff_filmstrip_muxer = {
  75     .name              = "filmstrip",
  76     .long_name         = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
  77     .extensions        = "flm",
  78     .priv_data_size    = sizeof(FilmstripMuxContext),
  79     .audio_codec       = AV_CODEC_ID_NONE,
  80     .video_codec       = AV_CODEC_ID_RAWVIDEO,
  81     .write_header      = write_header,
  82     .write_packet      = write_packet,
  83     .write_trailer     = write_trailer,
  84 };