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libavformat/mvi.c

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00001 /*
00002  * Motion Pixels MVI Demuxer
00003  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avformat.h"
00023 
00024 #define MVI_FRAC_BITS 10
00025 
00026 #define MVI_AUDIO_STREAM_INDEX 0
00027 #define MVI_VIDEO_STREAM_INDEX 1
00028 
00029 typedef struct MviDemuxContext {
00030     unsigned int (*get_int)(ByteIOContext *);
00031     uint32_t audio_data_size;
00032     uint64_t audio_size_counter;
00033     uint64_t audio_frame_size;
00034     int audio_size_left;
00035     int video_frame_size;
00036 } MviDemuxContext;
00037 
00038 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
00039 {
00040     MviDemuxContext *mvi = s->priv_data;
00041     ByteIOContext *pb = s->pb;
00042     AVStream *ast, *vst;
00043     unsigned int version, frames_count, msecs_per_frame, player_version;
00044 
00045     ast = av_new_stream(s, 0);
00046     if (!ast)
00047         return AVERROR(ENOMEM);
00048 
00049     vst = av_new_stream(s, 0);
00050     if (!vst)
00051         return AVERROR(ENOMEM);
00052 
00053     vst->codec->extradata_size = 2;
00054     vst->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
00055 
00056     version                  = get_byte(pb);
00057     vst->codec->extradata[0] = get_byte(pb);
00058     vst->codec->extradata[1] = get_byte(pb);
00059     frames_count             = get_le32(pb);
00060     msecs_per_frame          = get_le32(pb);
00061     vst->codec->width        = get_le16(pb);
00062     vst->codec->height       = get_le16(pb);
00063     get_byte(pb);
00064     ast->codec->sample_rate  = get_le16(pb);
00065     mvi->audio_data_size     = get_le32(pb);
00066     get_byte(pb);
00067     player_version           = get_le32(pb);
00068     get_le16(pb);
00069     get_byte(pb);
00070 
00071     if (frames_count == 0 || mvi->audio_data_size == 0)
00072         return AVERROR_INVALIDDATA;
00073 
00074     if (version != 7 || player_version > 213) {
00075         av_log(s, AV_LOG_ERROR, "unhandled version (%d,%d)\n", version, player_version);
00076         return AVERROR_INVALIDDATA;
00077     }
00078 
00079     av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
00080     ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;
00081     ast->codec->codec_id        = CODEC_ID_PCM_U8;
00082     ast->codec->channels        = 1;
00083     ast->codec->bits_per_coded_sample = 8;
00084     ast->codec->bit_rate        = ast->codec->sample_rate * 8;
00085 
00086     av_set_pts_info(vst, 64, msecs_per_frame, 1000000);
00087     vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00088     vst->codec->codec_id   = CODEC_ID_MOTIONPIXELS;
00089 
00090     mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? get_le16 : get_le24;
00091 
00092     mvi->audio_frame_size   = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
00093     mvi->audio_size_counter = (ast->codec->sample_rate * 830 / mvi->audio_frame_size - 1) * mvi->audio_frame_size;
00094     mvi->audio_size_left    = mvi->audio_data_size;
00095 
00096     return 0;
00097 }
00098 
00099 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00100 {
00101     int ret, count;
00102     MviDemuxContext *mvi = s->priv_data;
00103     ByteIOContext *pb = s->pb;
00104 
00105     if (mvi->video_frame_size == 0) {
00106         mvi->video_frame_size = (mvi->get_int)(pb);
00107         if (mvi->audio_size_left == 0)
00108             return AVERROR(EIO);
00109         count = (mvi->audio_size_counter + mvi->audio_frame_size + 512) >> MVI_FRAC_BITS;
00110         if (count > mvi->audio_size_left)
00111             count = mvi->audio_size_left;
00112         if ((ret = av_get_packet(pb, pkt, count)) < 0)
00113             return ret;
00114         pkt->stream_index = MVI_AUDIO_STREAM_INDEX;
00115         mvi->audio_size_left -= count;
00116         mvi->audio_size_counter += mvi->audio_frame_size - (count << MVI_FRAC_BITS);
00117     } else {
00118         if ((ret = av_get_packet(pb, pkt, mvi->video_frame_size)) < 0)
00119             return ret;
00120         pkt->stream_index = MVI_VIDEO_STREAM_INDEX;
00121         mvi->video_frame_size = 0;
00122     }
00123     return 0;
00124 }
00125 
00126 AVInputFormat mvi_demuxer = {
00127     "mvi",
00128     NULL_IF_CONFIG_SMALL("Motion Pixels MVI format"),
00129     sizeof(MviDemuxContext),
00130     NULL,
00131     read_header,
00132     read_packet,
00133     .extensions = "mvi"
00134 };

Generated on Fri Sep 16 2011 17:17:49 for FFmpeg by  doxygen 1.7.1