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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 Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; 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 #include "internal.h"
00024 
00025 #define MVI_FRAC_BITS 10
00026 
00027 #define MVI_AUDIO_STREAM_INDEX 0
00028 #define MVI_VIDEO_STREAM_INDEX 1
00029 
00030 typedef struct MviDemuxContext {
00031     unsigned int (*get_int)(AVIOContext *);
00032     uint32_t audio_data_size;
00033     uint64_t audio_size_counter;
00034     uint64_t audio_frame_size;
00035     int audio_size_left;
00036     int video_frame_size;
00037 } MviDemuxContext;
00038 
00039 static int read_header(AVFormatContext *s, AVFormatParameters *ap)
00040 {
00041     MviDemuxContext *mvi = s->priv_data;
00042     AVIOContext *pb = s->pb;
00043     AVStream *ast, *vst;
00044     unsigned int version, frames_count, msecs_per_frame, player_version;
00045 
00046     ast = avformat_new_stream(s, NULL);
00047     if (!ast)
00048         return AVERROR(ENOMEM);
00049 
00050     vst = avformat_new_stream(s, NULL);
00051     if (!vst)
00052         return AVERROR(ENOMEM);
00053 
00054     vst->codec->extradata_size = 2;
00055     vst->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
00056 
00057     version                  = avio_r8(pb);
00058     vst->codec->extradata[0] = avio_r8(pb);
00059     vst->codec->extradata[1] = avio_r8(pb);
00060     frames_count             = avio_rl32(pb);
00061     msecs_per_frame          = avio_rl32(pb);
00062     vst->codec->width        = avio_rl16(pb);
00063     vst->codec->height       = avio_rl16(pb);
00064     avio_r8(pb);
00065     ast->codec->sample_rate  = avio_rl16(pb);
00066     mvi->audio_data_size     = avio_rl32(pb);
00067     avio_r8(pb);
00068     player_version           = avio_rl32(pb);
00069     avio_rl16(pb);
00070     avio_r8(pb);
00071 
00072     if (frames_count == 0 || mvi->audio_data_size == 0)
00073         return AVERROR_INVALIDDATA;
00074 
00075     if (version != 7 || player_version > 213) {
00076         av_log(s, AV_LOG_ERROR, "unhandled version (%d,%d)\n", version, player_version);
00077         return AVERROR_INVALIDDATA;
00078     }
00079 
00080     avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
00081     ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;
00082     ast->codec->codec_id        = CODEC_ID_PCM_U8;
00083     ast->codec->channels        = 1;
00084     ast->codec->bits_per_coded_sample = 8;
00085     ast->codec->bit_rate        = ast->codec->sample_rate * 8;
00086 
00087     avpriv_set_pts_info(vst, 64, msecs_per_frame, 1000000);
00088     vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00089     vst->codec->codec_id   = CODEC_ID_MOTIONPIXELS;
00090 
00091     mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? avio_rl16 : avio_rl24;
00092 
00093     mvi->audio_frame_size   = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
00094     mvi->audio_size_counter = (ast->codec->sample_rate * 830 / mvi->audio_frame_size - 1) * mvi->audio_frame_size;
00095     mvi->audio_size_left    = mvi->audio_data_size;
00096 
00097     return 0;
00098 }
00099 
00100 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00101 {
00102     int ret, count;
00103     MviDemuxContext *mvi = s->priv_data;
00104     AVIOContext *pb = s->pb;
00105 
00106     if (mvi->video_frame_size == 0) {
00107         mvi->video_frame_size = (mvi->get_int)(pb);
00108         if (mvi->audio_size_left == 0)
00109             return AVERROR(EIO);
00110         count = (mvi->audio_size_counter + mvi->audio_frame_size + 512) >> MVI_FRAC_BITS;
00111         if (count > mvi->audio_size_left)
00112             count = mvi->audio_size_left;
00113         if ((ret = av_get_packet(pb, pkt, count)) < 0)
00114             return ret;
00115         pkt->stream_index = MVI_AUDIO_STREAM_INDEX;
00116         mvi->audio_size_left -= count;
00117         mvi->audio_size_counter += mvi->audio_frame_size - (count << MVI_FRAC_BITS);
00118     } else {
00119         if ((ret = av_get_packet(pb, pkt, mvi->video_frame_size)) < 0)
00120             return ret;
00121         pkt->stream_index = MVI_VIDEO_STREAM_INDEX;
00122         mvi->video_frame_size = 0;
00123     }
00124     return 0;
00125 }
00126 
00127 AVInputFormat ff_mvi_demuxer = {
00128     .name           = "mvi",
00129     .long_name      = NULL_IF_CONFIG_SMALL("Motion Pixels MVI format"),
00130     .priv_data_size = sizeof(MviDemuxContext),
00131     .read_header    = read_header,
00132     .read_packet    = read_packet,
00133     .extensions = "mvi"
00134 };
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