Libav 0.7.1
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00001 /* 00002 * LXF demuxer 00003 * Copyright (c) 2010 Tomas Härdin 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 "libavutil/intreadwrite.h" 00023 #include "avformat.h" 00024 #include "riff.h" 00025 00026 #define LXF_PACKET_HEADER_SIZE 60 00027 #define LXF_HEADER_DATA_SIZE 120 00028 #define LXF_IDENT "LEITCH\0" 00029 #define LXF_IDENT_LENGTH 8 00030 #define LXF_SAMPLERATE 48000 00031 #define LXF_MAX_AUDIO_PACKET (8008*15*4) ///< 15-channel 32-bit NTSC audio frame 00032 00033 static const AVCodecTag lxf_tags[] = { 00034 { CODEC_ID_MJPEG, 0 }, 00035 { CODEC_ID_MPEG1VIDEO, 1 }, 00036 { CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0 00037 { CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2 00038 { CODEC_ID_DVVIDEO, 4 }, //DV25 00039 { CODEC_ID_DVVIDEO, 5 }, //DVCPRO 00040 { CODEC_ID_DVVIDEO, 6 }, //DVCPRO50 00041 { CODEC_ID_RAWVIDEO, 7 }, //PIX_FMT_ARGB, where alpha is used for chroma keying 00042 { CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key 00043 { CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop") 00044 { CODEC_ID_NONE, 0 }, 00045 }; 00046 00047 typedef struct { 00048 int channels; 00049 uint8_t temp[LXF_MAX_AUDIO_PACKET]; 00050 int frame_number; 00051 } LXFDemuxContext; 00052 00053 static int lxf_probe(AVProbeData *p) 00054 { 00055 if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH)) 00056 return AVPROBE_SCORE_MAX; 00057 00058 return 0; 00059 } 00060 00067 static int check_checksum(const uint8_t *header) 00068 { 00069 int x; 00070 uint32_t sum = 0; 00071 00072 for (x = 0; x < LXF_PACKET_HEADER_SIZE; x += 4) 00073 sum += AV_RL32(&header[x]); 00074 00075 return sum; 00076 } 00077 00084 static int sync(AVFormatContext *s, uint8_t *header) 00085 { 00086 uint8_t buf[LXF_IDENT_LENGTH]; 00087 int ret; 00088 00089 if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH) 00090 return ret < 0 ? ret : AVERROR_EOF; 00091 00092 while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) { 00093 if (s->pb->eof_reached) 00094 return AVERROR_EOF; 00095 00096 memmove(buf, &buf[1], LXF_IDENT_LENGTH-1); 00097 buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb); 00098 } 00099 00100 memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH); 00101 00102 return 0; 00103 } 00104 00112 static int get_packet_header(AVFormatContext *s, uint8_t *header, uint32_t *format) 00113 { 00114 AVIOContext *pb = s->pb; 00115 int track_size, samples, ret; 00116 AVStream *st; 00117 00118 //find and read the ident 00119 if ((ret = sync(s, header)) < 0) 00120 return ret; 00121 00122 //read the rest of the packet header 00123 if ((ret = avio_read(pb, header + LXF_IDENT_LENGTH, 00124 LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH)) != 00125 LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH) { 00126 return ret < 0 ? ret : AVERROR_EOF; 00127 } 00128 00129 if (check_checksum(header)) 00130 av_log(s, AV_LOG_ERROR, "checksum error\n"); 00131 00132 *format = AV_RL32(&header[32]); 00133 ret = AV_RL32(&header[36]); 00134 00135 //type 00136 switch (AV_RL32(&header[16])) { 00137 case 0: 00138 //video 00139 //skip VBI data and metadata 00140 avio_skip(pb, (int64_t)(uint32_t)AV_RL32(&header[44]) + 00141 (int64_t)(uint32_t)AV_RL32(&header[52])); 00142 break; 00143 case 1: 00144 //audio 00145 if (!(st = s->streams[1])) { 00146 av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n"); 00147 break; 00148 } 00149 00150 //set codec based on specified audio bitdepth 00151 //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment 00152 *format = AV_RL32(&header[40]); 00153 st->codec->bits_per_coded_sample = (*format >> 6) & 0x3F; 00154 00155 if (st->codec->bits_per_coded_sample != (*format & 0x3F)) { 00156 av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n"); 00157 return AVERROR_PATCHWELCOME; 00158 } 00159 00160 switch (st->codec->bits_per_coded_sample) { 00161 case 16: st->codec->codec_id = CODEC_ID_PCM_S16LE; break; 00162 case 20: st->codec->codec_id = CODEC_ID_PCM_LXF; break; 00163 case 24: st->codec->codec_id = CODEC_ID_PCM_S24LE; break; 00164 case 32: st->codec->codec_id = CODEC_ID_PCM_S32LE; break; 00165 default: 00166 av_log(s, AV_LOG_WARNING, 00167 "only 16-, 20-, 24- and 32-bit PCM currently supported\n"); 00168 return AVERROR_PATCHWELCOME; 00169 } 00170 00171 track_size = AV_RL32(&header[48]); 00172 samples = track_size * 8 / st->codec->bits_per_coded_sample; 00173 00174 //use audio packet size to determine video standard 00175 //for NTSC we have one 8008-sample audio frame per five video frames 00176 if (samples == LXF_SAMPLERATE * 5005 / 30000) { 00177 av_set_pts_info(s->streams[0], 64, 1001, 30000); 00178 } else { 00179 //assume PAL, but warn if we don't have 1920 samples 00180 if (samples != LXF_SAMPLERATE / 25) 00181 av_log(s, AV_LOG_WARNING, 00182 "video doesn't seem to be PAL or NTSC. guessing PAL\n"); 00183 00184 av_set_pts_info(s->streams[0], 64, 1, 25); 00185 } 00186 00187 //TODO: warning if track mask != (1 << channels) - 1? 00188 ret = av_popcount(AV_RL32(&header[44])) * track_size; 00189 00190 break; 00191 default: 00192 break; 00193 } 00194 00195 return ret; 00196 } 00197 00198 static int lxf_read_header(AVFormatContext *s, AVFormatParameters *ap) 00199 { 00200 LXFDemuxContext *lxf = s->priv_data; 00201 AVIOContext *pb = s->pb; 00202 uint8_t header[LXF_PACKET_HEADER_SIZE], header_data[LXF_HEADER_DATA_SIZE]; 00203 int ret; 00204 AVStream *st; 00205 uint32_t format, video_params, disk_params; 00206 uint16_t record_date, expiration_date; 00207 00208 if ((ret = get_packet_header(s, header, &format)) < 0) 00209 return ret; 00210 00211 if (ret != LXF_HEADER_DATA_SIZE) { 00212 av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n", 00213 LXF_HEADER_DATA_SIZE, ret); 00214 return AVERROR_INVALIDDATA; 00215 } 00216 00217 if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE) 00218 return ret < 0 ? ret : AVERROR_EOF; 00219 00220 if (!(st = av_new_stream(s, 0))) 00221 return AVERROR(ENOMEM); 00222 00223 st->duration = AV_RL32(&header_data[32]); 00224 video_params = AV_RL32(&header_data[40]); 00225 record_date = AV_RL16(&header_data[56]); 00226 expiration_date = AV_RL16(&header_data[58]); 00227 disk_params = AV_RL32(&header_data[116]); 00228 00229 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 00230 st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF); 00231 st->codec->codec_tag = video_params & 0xF; 00232 st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag); 00233 00234 av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n", 00235 record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF, 00236 (record_date >> 11) & 0x1F); 00237 00238 av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n", 00239 expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF, 00240 (expiration_date >> 11) & 0x1F); 00241 00242 if ((video_params >> 22) & 1) 00243 av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n"); 00244 00245 if ((lxf->channels = (disk_params >> 2) & 0xF)) { 00246 if (!(st = av_new_stream(s, 1))) 00247 return AVERROR(ENOMEM); 00248 00249 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 00250 st->codec->sample_rate = LXF_SAMPLERATE; 00251 st->codec->channels = lxf->channels; 00252 00253 av_set_pts_info(st, 64, 1, st->codec->sample_rate); 00254 } 00255 00256 if (format == 1) { 00257 //skip extended field data 00258 avio_skip(s->pb, (uint32_t)AV_RL32(&header[40])); 00259 } 00260 00261 return 0; 00262 } 00263 00271 static void deplanarize(LXFDemuxContext *lxf, AVStream *ast, uint8_t *out, int bytes) 00272 { 00273 int x, y, z, i, bytes_per_sample = ast->codec->bits_per_coded_sample >> 3; 00274 00275 for (z = i = 0; z < lxf->channels; z++) 00276 for (y = 0; y < bytes / bytes_per_sample / lxf->channels; y++) 00277 for (x = 0; x < bytes_per_sample; x++, i++) 00278 out[x + bytes_per_sample*(z + y*lxf->channels)] = lxf->temp[i]; 00279 } 00280 00281 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt) 00282 { 00283 LXFDemuxContext *lxf = s->priv_data; 00284 AVIOContext *pb = s->pb; 00285 uint8_t header[LXF_PACKET_HEADER_SIZE], *buf; 00286 AVStream *ast = NULL; 00287 uint32_t stream, format; 00288 int ret, ret2; 00289 00290 if ((ret = get_packet_header(s, header, &format)) < 0) 00291 return ret; 00292 00293 stream = AV_RL32(&header[16]); 00294 00295 if (stream > 1) { 00296 av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream); 00297 return AVERROR(EAGAIN); 00298 } 00299 00300 if (stream == 1 && !(ast = s->streams[1])) { 00301 av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n"); 00302 return AVERROR_INVALIDDATA; 00303 } 00304 00305 //make sure the data fits in the de-planerization buffer 00306 if (ast && ret > LXF_MAX_AUDIO_PACKET) { 00307 av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n", 00308 ret, LXF_MAX_AUDIO_PACKET); 00309 return AVERROR_INVALIDDATA; 00310 } 00311 00312 if ((ret2 = av_new_packet(pkt, ret)) < 0) 00313 return ret2; 00314 00315 //read non-20-bit audio data into lxf->temp so we can deplanarize it 00316 buf = ast && ast->codec->codec_id != CODEC_ID_PCM_LXF ? lxf->temp : pkt->data; 00317 00318 if ((ret2 = avio_read(pb, buf, ret)) != ret) { 00319 av_free_packet(pkt); 00320 return ret2 < 0 ? ret2 : AVERROR_EOF; 00321 } 00322 00323 pkt->stream_index = stream; 00324 00325 if (ast) { 00326 if(ast->codec->codec_id != CODEC_ID_PCM_LXF) 00327 deplanarize(lxf, ast, pkt->data, ret); 00328 } else { 00329 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B) 00330 if (((format >> 22) & 0x3) < 2) 00331 pkt->flags |= AV_PKT_FLAG_KEY; 00332 00333 pkt->dts = lxf->frame_number++; 00334 } 00335 00336 return ret; 00337 } 00338 00339 AVInputFormat ff_lxf_demuxer = { 00340 .name = "lxf", 00341 .long_name = NULL_IF_CONFIG_SMALL("VR native stream format (LXF)"), 00342 .priv_data_size = sizeof(LXFDemuxContext), 00343 .read_probe = lxf_probe, 00344 .read_header = lxf_read_header, 00345 .read_packet = lxf_read_packet, 00346 .codec_tag = (const AVCodecTag* const []){lxf_tags, 0}, 00347 }; 00348