1/* 2 * LXF demuxer 3 * Copyright (c) 2010 Tomas H��rdin 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include <inttypes.h> 23 24#include "libavutil/intreadwrite.h" 25#include "libavcodec/bytestream.h" 26#include "avformat.h" 27#include "internal.h" 28 29#define LXF_MAX_PACKET_HEADER_SIZE 256 30#define LXF_HEADER_DATA_SIZE 120 31#define LXF_IDENT "LEITCH\0" 32#define LXF_IDENT_LENGTH 8 33#define LXF_SAMPLERATE 48000 34 35static const AVCodecTag lxf_tags[] = { 36 { AV_CODEC_ID_MJPEG, 0 }, 37 { AV_CODEC_ID_MPEG1VIDEO, 1 }, 38 { AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0 39 { AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2 40 { AV_CODEC_ID_DVVIDEO, 4 }, //DV25 41 { AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO 42 { AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50 43 { AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying 44 { AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key 45 { AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop") 46 { AV_CODEC_ID_NONE, 0 }, 47}; 48 49typedef struct { 50 int channels; ///< number of audio channels. zero means no audio 51 int frame_number; ///< current video frame 52 uint32_t video_format, packet_type, extended_size; 53} LXFDemuxContext; 54 55static int lxf_probe(AVProbeData *p) 56{ 57 if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH)) 58 return AVPROBE_SCORE_MAX; 59 60 return 0; 61} 62 63/** 64 * Verify the checksum of an LXF packet header 65 * 66 * @param[in] header the packet header to check 67 * @return zero if the checksum is OK, non-zero otherwise 68 */ 69static int check_checksum(const uint8_t *header, int size) 70{ 71 int x; 72 uint32_t sum = 0; 73 74 for (x = 0; x < size; x += 4) 75 sum += AV_RL32(&header[x]); 76 77 return sum; 78} 79 80/** 81 * Read input until we find the next ident. If found, copy it to the header buffer 82 * 83 * @param[out] header where to copy the ident to 84 * @return 0 if an ident was found, < 0 on I/O error 85 */ 86static int sync(AVFormatContext *s, uint8_t *header) 87{ 88 uint8_t buf[LXF_IDENT_LENGTH]; 89 int ret; 90 91 if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH) 92 return ret < 0 ? ret : AVERROR_EOF; 93 94 while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) { 95 if (url_feof(s->pb)) 96 return AVERROR_EOF; 97 98 memmove(buf, &buf[1], LXF_IDENT_LENGTH-1); 99 buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb); 100 } 101 102 memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH); 103 104 return 0; 105} 106 107/** 108 * Read and checksum the next packet header 109 * 110 * @return the size of the payload following the header or < 0 on failure 111 */ 112static int get_packet_header(AVFormatContext *s) 113{ 114 LXFDemuxContext *lxf = s->priv_data; 115 AVIOContext *pb = s->pb; 116 int track_size, samples, ret; 117 uint32_t version, audio_format, header_size, channels, tmp; 118 AVStream *st; 119 uint8_t header[LXF_MAX_PACKET_HEADER_SIZE]; 120 const uint8_t *p = header + LXF_IDENT_LENGTH; 121 122 //find and read the ident 123 if ((ret = sync(s, header)) < 0) 124 return ret; 125 126 ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8); 127 if (ret != 8) 128 return ret < 0 ? ret : AVERROR_EOF; 129 130 version = bytestream_get_le32(&p); 131 header_size = bytestream_get_le32(&p); 132 if (version > 1) 133 avpriv_request_sample(s, "Unknown format version %"PRIu32"\n", version); 134 135 if (header_size < (version ? 72 : 60) || 136 header_size > LXF_MAX_PACKET_HEADER_SIZE || 137 (header_size & 3)) { 138 av_log(s, AV_LOG_ERROR, "Invalid header size 0x%"PRIx32"\n", header_size); 139 return AVERROR_INVALIDDATA; 140 } 141 142 //read the rest of the packet header 143 if ((ret = avio_read(pb, header + (p - header), 144 header_size - (p - header))) != 145 header_size - (p - header)) 146 return ret < 0 ? ret : AVERROR_EOF; 147 148 if (check_checksum(header, header_size)) 149 av_log(s, AV_LOG_ERROR, "checksum error\n"); 150 151 lxf->packet_type = bytestream_get_le32(&p); 152 p += version ? 20 : 12; 153 154 lxf->extended_size = 0; 155 switch (lxf->packet_type) { 156 case 0: 157 //video 158 lxf->video_format = bytestream_get_le32(&p); 159 ret = bytestream_get_le32(&p); 160 //skip VBI data and metadata 161 avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) + 162 (int64_t)(uint32_t)AV_RL32(p + 12)); 163 break; 164 case 1: 165 //audio 166 if (s->nb_streams < 2) { 167 av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n"); 168 break; 169 } 170 171 if (version == 0) 172 p += 8; 173 audio_format = bytestream_get_le32(&p); 174 channels = bytestream_get_le32(&p); 175 track_size = bytestream_get_le32(&p); 176 177 st = s->streams[1]; 178 179 //set codec based on specified audio bitdepth 180 //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment 181 st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F; 182 183 if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) { 184 av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n"); 185 return AVERROR_PATCHWELCOME; 186 } 187 188 switch (st->codec->bits_per_coded_sample) { 189 case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break; 190 case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF; break; 191 case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break; 192 case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break; 193 default: 194 av_log(s, AV_LOG_WARNING, 195 "only 16-, 20-, 24- and 32-bit PCM currently supported\n"); 196 return AVERROR_PATCHWELCOME; 197 } 198 199 samples = track_size * 8 / st->codec->bits_per_coded_sample; 200 201 //use audio packet size to determine video standard 202 //for NTSC we have one 8008-sample audio frame per five video frames 203 if (samples == LXF_SAMPLERATE * 5005 / 30000) { 204 avpriv_set_pts_info(s->streams[0], 64, 1001, 30000); 205 } else { 206 //assume PAL, but warn if we don't have 1920 samples 207 if (samples != LXF_SAMPLERATE / 25) 208 av_log(s, AV_LOG_WARNING, 209 "video doesn't seem to be PAL or NTSC. guessing PAL\n"); 210 211 avpriv_set_pts_info(s->streams[0], 64, 1, 25); 212 } 213 214 //TODO: warning if track mask != (1 << channels) - 1? 215 ret = av_popcount(channels) * track_size; 216 217 break; 218 default: 219 tmp = bytestream_get_le32(&p); 220 ret = bytestream_get_le32(&p); 221 if (tmp == 1) 222 lxf->extended_size = bytestream_get_le32(&p); 223 break; 224 } 225 226 return ret; 227} 228 229static int lxf_read_header(AVFormatContext *s) 230{ 231 LXFDemuxContext *lxf = s->priv_data; 232 AVIOContext *pb = s->pb; 233 uint8_t header_data[LXF_HEADER_DATA_SIZE]; 234 int ret; 235 AVStream *st; 236 uint32_t video_params, disk_params; 237 uint16_t record_date, expiration_date; 238 239 if ((ret = get_packet_header(s)) < 0) 240 return ret; 241 242 if (ret != LXF_HEADER_DATA_SIZE) { 243 av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n", 244 LXF_HEADER_DATA_SIZE, ret); 245 return AVERROR_INVALIDDATA; 246 } 247 248 if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE) 249 return ret < 0 ? ret : AVERROR_EOF; 250 251 if (!(st = avformat_new_stream(s, NULL))) 252 return AVERROR(ENOMEM); 253 254 st->duration = AV_RL32(&header_data[32]); 255 video_params = AV_RL32(&header_data[40]); 256 record_date = AV_RL16(&header_data[56]); 257 expiration_date = AV_RL16(&header_data[58]); 258 disk_params = AV_RL32(&header_data[116]); 259 260 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 261 st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF); 262 st->codec->codec_tag = video_params & 0xF; 263 st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag); 264 st->need_parsing = AVSTREAM_PARSE_HEADERS; 265 266 av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n", 267 record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF, 268 (record_date >> 11) & 0x1F); 269 270 av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n", 271 expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF, 272 (expiration_date >> 11) & 0x1F); 273 274 if ((video_params >> 22) & 1) 275 av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n"); 276 277 if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) { 278 if (!(st = avformat_new_stream(s, NULL))) 279 return AVERROR(ENOMEM); 280 281 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 282 st->codec->sample_rate = LXF_SAMPLERATE; 283 st->codec->channels = lxf->channels; 284 285 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); 286 } 287 288 avio_skip(s->pb, lxf->extended_size); 289 290 return 0; 291} 292 293static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt) 294{ 295 LXFDemuxContext *lxf = s->priv_data; 296 AVIOContext *pb = s->pb; 297 uint32_t stream; 298 int ret, ret2; 299 300 if ((ret = get_packet_header(s)) < 0) 301 return ret; 302 303 stream = lxf->packet_type; 304 305 if (stream > 1) { 306 av_log(s, AV_LOG_WARNING, 307 "got packet with illegal stream index %"PRIu32"\n", stream); 308 return AVERROR(EAGAIN); 309 } 310 311 if (stream == 1 && s->nb_streams < 2) { 312 av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n"); 313 return AVERROR_INVALIDDATA; 314 } 315 316 if ((ret2 = av_new_packet(pkt, ret)) < 0) 317 return ret2; 318 319 if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) { 320 av_free_packet(pkt); 321 return ret2 < 0 ? ret2 : AVERROR_EOF; 322 } 323 324 pkt->stream_index = stream; 325 326 if (!stream) { 327 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B) 328 if (((lxf->video_format >> 22) & 0x3) < 2) 329 pkt->flags |= AV_PKT_FLAG_KEY; 330 331 pkt->dts = lxf->frame_number++; 332 } 333 334 return ret; 335} 336 337AVInputFormat ff_lxf_demuxer = { 338 .name = "lxf", 339 .long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"), 340 .priv_data_size = sizeof(LXFDemuxContext), 341 .read_probe = lxf_probe, 342 .read_header = lxf_read_header, 343 .read_packet = lxf_read_packet, 344 .codec_tag = (const AVCodecTag* const []){lxf_tags, 0}, 345}; 346