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ffmpeg / libavformat / mvi.c @ e63a3628

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/*
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 * Motion Pixels MVI Demuxer
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 * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "avformat.h"
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#define MVI_FRAC_BITS 10
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#define MVI_AUDIO_STREAM_INDEX 0
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#define MVI_VIDEO_STREAM_INDEX 1
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typedef struct MviDemuxContext {
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    unsigned int (*get_int)(AVIOContext *);
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    uint32_t audio_data_size;
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    uint64_t audio_size_counter;
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    uint64_t audio_frame_size;
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    int audio_size_left;
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    int video_frame_size;
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} MviDemuxContext;
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static int read_header(AVFormatContext *s, AVFormatParameters *ap)
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{
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    MviDemuxContext *mvi = s->priv_data;
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    AVIOContext *pb = s->pb;
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    AVStream *ast, *vst;
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    unsigned int version, frames_count, msecs_per_frame, player_version;
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    ast = av_new_stream(s, 0);
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    if (!ast)
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        return AVERROR(ENOMEM);
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    vst = av_new_stream(s, 0);
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    if (!vst)
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        return AVERROR(ENOMEM);
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    vst->codec->extradata_size = 2;
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    vst->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
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    version                  = avio_r8(pb);
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    vst->codec->extradata[0] = avio_r8(pb);
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    vst->codec->extradata[1] = avio_r8(pb);
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    frames_count             = avio_rl32(pb);
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    msecs_per_frame          = avio_rl32(pb);
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    vst->codec->width        = avio_rl16(pb);
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    vst->codec->height       = avio_rl16(pb);
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    avio_r8(pb);
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    ast->codec->sample_rate  = avio_rl16(pb);
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    mvi->audio_data_size     = avio_rl32(pb);
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    avio_r8(pb);
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    player_version           = avio_rl32(pb);
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    avio_rl16(pb);
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    avio_r8(pb);
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    if (frames_count == 0 || mvi->audio_data_size == 0)
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        return AVERROR_INVALIDDATA;
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    if (version != 7 || player_version > 213) {
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        av_log(s, AV_LOG_ERROR, "unhandled version (%d,%d)\n", version, player_version);
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        return AVERROR_INVALIDDATA;
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    }
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    av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
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    ast->codec->codec_type      = AVMEDIA_TYPE_AUDIO;
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    ast->codec->codec_id        = CODEC_ID_PCM_U8;
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    ast->codec->channels        = 1;
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    ast->codec->bits_per_coded_sample = 8;
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    ast->codec->bit_rate        = ast->codec->sample_rate * 8;
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    av_set_pts_info(vst, 64, msecs_per_frame, 1000000);
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    vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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    vst->codec->codec_id   = CODEC_ID_MOTIONPIXELS;
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    mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? avio_rl16 : avio_rl24;
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    mvi->audio_frame_size   = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
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    mvi->audio_size_counter = (ast->codec->sample_rate * 830 / mvi->audio_frame_size - 1) * mvi->audio_frame_size;
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    mvi->audio_size_left    = mvi->audio_data_size;
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    return 0;
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}
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static int read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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    int ret, count;
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    MviDemuxContext *mvi = s->priv_data;
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    AVIOContext *pb = s->pb;
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    if (mvi->video_frame_size == 0) {
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        mvi->video_frame_size = (mvi->get_int)(pb);
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        if (mvi->audio_size_left == 0)
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            return AVERROR(EIO);
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        count = (mvi->audio_size_counter + mvi->audio_frame_size + 512) >> MVI_FRAC_BITS;
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        if (count > mvi->audio_size_left)
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            count = mvi->audio_size_left;
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        if ((ret = av_get_packet(pb, pkt, count)) < 0)
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            return ret;
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        pkt->stream_index = MVI_AUDIO_STREAM_INDEX;
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        mvi->audio_size_left -= count;
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        mvi->audio_size_counter += mvi->audio_frame_size - (count << MVI_FRAC_BITS);
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    } else {
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        if ((ret = av_get_packet(pb, pkt, mvi->video_frame_size)) < 0)
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            return ret;
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        pkt->stream_index = MVI_VIDEO_STREAM_INDEX;
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        mvi->video_frame_size = 0;
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    }
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    return 0;
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}
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AVInputFormat ff_mvi_demuxer = {
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    "mvi",
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    NULL_IF_CONFIG_SMALL("Motion Pixels MVI format"),
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    sizeof(MviDemuxContext),
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    NULL,
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    read_header,
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    read_packet,
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    .extensions = "mvi"
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};