Libav 0.7.1
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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 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)(AVIOContext *); 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 AVIOContext *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 = avio_r8(pb); 00057 vst->codec->extradata[0] = avio_r8(pb); 00058 vst->codec->extradata[1] = avio_r8(pb); 00059 frames_count = avio_rl32(pb); 00060 msecs_per_frame = avio_rl32(pb); 00061 vst->codec->width = avio_rl16(pb); 00062 vst->codec->height = avio_rl16(pb); 00063 avio_r8(pb); 00064 ast->codec->sample_rate = avio_rl16(pb); 00065 mvi->audio_data_size = avio_rl32(pb); 00066 avio_r8(pb); 00067 player_version = avio_rl32(pb); 00068 avio_rl16(pb); 00069 avio_r8(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)) ? avio_rl16 : avio_rl24; 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 AVIOContext *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 ff_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 };