Libav
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00001 /* 00002 * 8088flex TMV file demuxer 00003 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu> 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 00029 #include "libavutil/intreadwrite.h" 00030 #include "avformat.h" 00031 00032 enum { 00033 TMV_PADDING = 0x01, 00034 TMV_STEREO = 0x02, 00035 }; 00036 00037 #define TMV_TAG MKTAG('T', 'M', 'A', 'V') 00038 00039 typedef struct TMVContext { 00040 unsigned audio_chunk_size; 00041 unsigned video_chunk_size; 00042 unsigned padding; 00043 unsigned stream_index; 00044 } TMVContext; 00045 00046 #define TMV_HEADER_SIZE 12 00047 00048 #define PROBE_MIN_SAMPLE_RATE 5000 00049 #define PROBE_MAX_FPS 120 00050 #define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS) 00051 00052 static int tmv_probe(AVProbeData *p) 00053 { 00054 if (AV_RL32(p->buf) == TMV_TAG && 00055 AV_RL16(p->buf+4) >= PROBE_MIN_SAMPLE_RATE && 00056 AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE && 00057 !p->buf[8] && // compression method 00058 p->buf[9] && // char cols 00059 p->buf[10]) // char rows 00060 return AVPROBE_SCORE_MAX / 00061 ((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4); 00062 return 0; 00063 } 00064 00065 static int tmv_read_header(AVFormatContext *s, AVFormatParameters *ap) 00066 { 00067 TMVContext *tmv = s->priv_data; 00068 ByteIOContext *pb = s->pb; 00069 AVStream *vst, *ast; 00070 AVRational fps; 00071 unsigned comp_method, char_cols, char_rows, features; 00072 00073 if (get_le32(pb) != TMV_TAG) 00074 return -1; 00075 00076 if (!(vst = av_new_stream(s, 0))) 00077 return AVERROR(ENOMEM); 00078 00079 if (!(ast = av_new_stream(s, 0))) 00080 return AVERROR(ENOMEM); 00081 00082 ast->codec->sample_rate = get_le16(pb); 00083 if (!ast->codec->sample_rate) { 00084 av_log(s, AV_LOG_ERROR, "invalid sample rate\n"); 00085 return -1; 00086 } 00087 00088 tmv->audio_chunk_size = get_le16(pb); 00089 if (!tmv->audio_chunk_size) { 00090 av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n"); 00091 return -1; 00092 } 00093 00094 comp_method = get_byte(pb); 00095 if (comp_method) { 00096 av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n", 00097 comp_method); 00098 return -1; 00099 } 00100 00101 char_cols = get_byte(pb); 00102 char_rows = get_byte(pb); 00103 tmv->video_chunk_size = char_cols * char_rows * 2; 00104 00105 features = get_byte(pb); 00106 if (features & ~(TMV_PADDING | TMV_STEREO)) { 00107 av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n", 00108 features & ~(TMV_PADDING | TMV_STEREO)); 00109 return -1; 00110 } 00111 00112 ast->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00113 ast->codec->codec_id = CODEC_ID_PCM_U8; 00114 ast->codec->channels = features & TMV_STEREO ? 2 : 1; 00115 ast->codec->bits_per_coded_sample = 8; 00116 ast->codec->bit_rate = ast->codec->sample_rate * 00117 ast->codec->bits_per_coded_sample; 00118 av_set_pts_info(ast, 32, 1, ast->codec->sample_rate); 00119 00120 fps.num = ast->codec->sample_rate * ast->codec->channels; 00121 fps.den = tmv->audio_chunk_size; 00122 av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL); 00123 00124 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00125 vst->codec->codec_id = CODEC_ID_TMV; 00126 vst->codec->pix_fmt = PIX_FMT_PAL8; 00127 vst->codec->width = char_cols * 8; 00128 vst->codec->height = char_rows * 8; 00129 av_set_pts_info(vst, 32, fps.den, fps.num); 00130 00131 if (features & TMV_PADDING) 00132 tmv->padding = 00133 ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) - 00134 (tmv->video_chunk_size + tmv->audio_chunk_size); 00135 00136 vst->codec->bit_rate = ((tmv->video_chunk_size + tmv->padding) * 00137 fps.num * 8) / fps.den; 00138 00139 return 0; 00140 } 00141 00142 static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt) 00143 { 00144 TMVContext *tmv = s->priv_data; 00145 ByteIOContext *pb = s->pb; 00146 int ret, pkt_size = tmv->stream_index ? 00147 tmv->audio_chunk_size : tmv->video_chunk_size; 00148 00149 if (url_feof(pb)) 00150 return AVERROR_EOF; 00151 00152 ret = av_get_packet(pb, pkt, pkt_size); 00153 00154 if (tmv->stream_index) 00155 url_fskip(pb, tmv->padding); 00156 00157 pkt->stream_index = tmv->stream_index; 00158 tmv->stream_index ^= 1; 00159 pkt->flags |= AV_PKT_FLAG_KEY; 00160 00161 return ret; 00162 } 00163 00164 static int tmv_read_seek(AVFormatContext *s, int stream_index, 00165 int64_t timestamp, int flags) 00166 { 00167 TMVContext *tmv = s->priv_data; 00168 int64_t pos; 00169 00170 if (stream_index) 00171 return -1; 00172 00173 pos = timestamp * 00174 (tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding); 00175 00176 url_fseek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET); 00177 tmv->stream_index = 0; 00178 return 0; 00179 } 00180 00181 AVInputFormat tmv_demuxer = { 00182 "tmv", 00183 NULL_IF_CONFIG_SMALL("8088flex TMV"), 00184 sizeof(TMVContext), 00185 tmv_probe, 00186 tmv_read_header, 00187 tmv_read_packet, 00188 NULL, 00189 tmv_read_seek, 00190 .flags = AVFMT_GENERIC_INDEX, 00191 };