libavformat/lxfdec.c

   1 /*
   2  * LXF demuxer
   3  * Copyright (c) 2010 Tomas Härdin
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/intreadwrite.h"
  23 #include "avformat.h"
  24 #include "internal.h"
  25
  26 #define LXF_PACKET_HEADER_SIZE  60
  27 #define LXF_HEADER_DATA_SIZE    120
  28 #define LXF_IDENT               "LEITCH\0"
  29 #define LXF_IDENT_LENGTH        8
  30 #define LXF_SAMPLERATE          48000
  31 #define LXF_MAX_AUDIO_PACKET    (8008*15*4) ///< 15-channel 32-bit NTSC audio frame
  32
  33 static const AVCodecTag lxf_tags[] = {
  34     { AV_CODEC_ID_MJPEG,       0 },
  35     { AV_CODEC_ID_MPEG1VIDEO,  1 },
  36     { AV_CODEC_ID_MPEG2VIDEO,  2 },    //MpMl, 4:2:0
  37     { AV_CODEC_ID_MPEG2VIDEO,  3 },    //MpPl, 4:2:2
  38     { AV_CODEC_ID_DVVIDEO,     4 },    //DV25
  39     { AV_CODEC_ID_DVVIDEO,     5 },    //DVCPRO
  40     { AV_CODEC_ID_DVVIDEO,     6 },    //DVCPRO50
  41     { AV_CODEC_ID_RAWVIDEO,    7 },    //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
  42     { AV_CODEC_ID_RAWVIDEO,    8 },    //16-bit chroma key
  43     { AV_CODEC_ID_MPEG2VIDEO,  9 },    //4:2:2 CBP ("Constrained Bytes per Gop")
  44     { AV_CODEC_ID_NONE,        0 },
  45 };
  46
  47 typedef struct {
  48     int channels;                       ///< number of audio channels. zero means no audio
  49     uint8_t temp[LXF_MAX_AUDIO_PACKET]; ///< temp buffer for de-planarizing the audio data
  50     int frame_number;                   ///< current video frame
  51 } LXFDemuxContext;
  52
  53 static int lxf_probe(AVProbeData *p)
  54 {
  55     if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
  56         return AVPROBE_SCORE_MAX;
  57
  58     return 0;
  59 }
  60
  61 /**
  62  * Verify the checksum of an LXF packet header
  63  *
  64  * @param[in] header the packet header to check
  65  * @return zero if the checksum is OK, non-zero otherwise
  66  */
  67 static int check_checksum(const uint8_t *header)
  68 {
  69     int x;
  70     uint32_t sum = 0;
  71
  72     for (x = 0; x < LXF_PACKET_HEADER_SIZE; x += 4)
  73         sum += AV_RL32(&header[x]);
  74
  75     return sum;
  76 }
  77
  78 /**
  79  * Read input until we find the next ident. If found, copy it to the header buffer
  80  *
  81  * @param[out] header where to copy the ident to
  82  * @return 0 if an ident was found, < 0 on I/O error
  83  */
  84 static int sync(AVFormatContext *s, uint8_t *header)
  85 {
  86     uint8_t buf[LXF_IDENT_LENGTH];
  87     int ret;
  88
  89     if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
  90         return ret < 0 ? ret : AVERROR_EOF;
  91
  92     while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
  93         if (s->pb->eof_reached)
  94             return AVERROR_EOF;
  95
  96         memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
  97         buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
  98     }
  99
 100     memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
 101
 102     return 0;
 103 }
 104
 105 /**
 106  * Read and checksum the next packet header
 107  *
 108  * @param[out] header the read packet header
 109  * @param[out] format context dependent format information
 110  * @return the size of the payload following the header or < 0 on failure
 111  */
 112 static int get_packet_header(AVFormatContext *s, uint8_t *header, uint32_t *format)
 113 {
 114     AVIOContext   *pb  = s->pb;
 115     int track_size, samples, ret;
 116     AVStream *st;
 117
 118     //find and read the ident
 119     if ((ret = sync(s, header)) < 0)
 120         return ret;
 121
 122     //read the rest of the packet header
 123     if ((ret = avio_read(pb, header + LXF_IDENT_LENGTH,
 124                           LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH)) !=
 125                           LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH) {
 126         return ret < 0 ? ret : AVERROR_EOF;
 127     }
 128
 129     if (check_checksum(header))
 130         av_log(s, AV_LOG_ERROR, "checksum error\n");
 131
 132     *format = AV_RL32(&header[32]);
 133     ret     = AV_RL32(&header[36]);
 134
 135     //type
 136     switch (AV_RL32(&header[16])) {
 137     case 0:
 138         //video
 139         //skip VBI data and metadata
 140         avio_skip(pb, (int64_t)(uint32_t)AV_RL32(&header[44]) +
 141                       (int64_t)(uint32_t)AV_RL32(&header[52]));
 142         break;
 143     case 1:
 144         //audio
 145         if (!(st = s->streams[1])) {
 146             av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
 147             break;
 148         }
 149
 150         //set codec based on specified audio bitdepth
 151         //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
 152         *format                          = AV_RL32(&header[40]);
 153         st->codec->bits_per_coded_sample = (*format >> 6) & 0x3F;
 154
 155         if (st->codec->bits_per_coded_sample != (*format & 0x3F)) {
 156             av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
 157             return AVERROR_PATCHWELCOME;
 158         }
 159
 160         switch (st->codec->bits_per_coded_sample) {
 161         case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE; break;
 162         case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF;   break;
 163         case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE; break;
 164         case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE; break;
 165         default:
 166             av_log(s, AV_LOG_WARNING,
 167                    "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
 168             return AVERROR_PATCHWELCOME;
 169         }
 170
 171         track_size = AV_RL32(&header[48]);
 172         samples = track_size * 8 / st->codec->bits_per_coded_sample;
 173
 174         //use audio packet size to determine video standard
 175         //for NTSC we have one 8008-sample audio frame per five video frames
 176         if (samples == LXF_SAMPLERATE * 5005 / 30000) {
 177             avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
 178         } else {
 179             //assume PAL, but warn if we don't have 1920 samples
 180             if (samples != LXF_SAMPLERATE / 25)
 181                 av_log(s, AV_LOG_WARNING,
 182                        "video doesn't seem to be PAL or NTSC. guessing PAL\n");
 183
 184             avpriv_set_pts_info(s->streams[0], 64, 1, 25);
 185         }
 186
 187         //TODO: warning if track mask != (1 << channels) - 1?
 188         ret = av_popcount(AV_RL32(&header[44])) * track_size;
 189
 190         break;
 191     default:
 192         break;
 193     }
 194
 195     return ret;
 196 }
 197
 198 static int lxf_read_header(AVFormatContext *s)
 199 {
 200     LXFDemuxContext *lxf = s->priv_data;
 201     AVIOContext   *pb  = s->pb;
 202     uint8_t header[LXF_PACKET_HEADER_SIZE], header_data[LXF_HEADER_DATA_SIZE];
 203     int ret;
 204     AVStream *st;
 205     uint32_t format, video_params, disk_params;
 206     uint16_t record_date, expiration_date;
 207
 208     if ((ret = get_packet_header(s, header, &format)) < 0)
 209         return ret;
 210
 211     if (ret != LXF_HEADER_DATA_SIZE) {
 212         av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
 213                LXF_HEADER_DATA_SIZE, ret);
 214         return AVERROR_INVALIDDATA;
 215     }
 216
 217     if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
 218         return ret < 0 ? ret : AVERROR_EOF;
 219
 220     if (!(st = avformat_new_stream(s, NULL)))
 221         return AVERROR(ENOMEM);
 222
 223     st->duration          = AV_RL32(&header_data[32]);
 224     video_params          = AV_RL32(&header_data[40]);
 225     record_date           = AV_RL16(&header_data[56]);
 226     expiration_date       = AV_RL16(&header_data[58]);
 227     disk_params           = AV_RL32(&header_data[116]);
 228
 229     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
 230     st->codec->bit_rate   = 1000000 * ((video_params >> 14) & 0xFF);
 231     st->codec->codec_tag  = video_params & 0xF;
 232     st->codec->codec_id   = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
 233
 234     av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
 235            record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
 236            (record_date >> 11) & 0x1F);
 237
 238     av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
 239            expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
 240            (expiration_date >> 11) & 0x1F);
 241
 242     if ((video_params >> 22) & 1)
 243         av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
 244
 245     if ((lxf->channels = (disk_params >> 2) & 0xF)) {
 246         if (!(st = avformat_new_stream(s, NULL)))
 247             return AVERROR(ENOMEM);
 248
 249         st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
 250         st->codec->sample_rate = LXF_SAMPLERATE;
 251         st->codec->channels    = lxf->channels;
 252
 253         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 254     }
 255
 256     if (format == 1) {
 257         //skip extended field data
 258         avio_skip(s->pb, (uint32_t)AV_RL32(&header[40]));
 259     }
 260
 261     return 0;
 262 }
 263
 264 /**
 265  * De-planerize the PCM data in lxf->temp
 266  * FIXME: remove this once support for planar audio is added to libavcodec
 267  *
 268  * @param[out] out where to write the de-planerized data to
 269  * @param[in] bytes the total size of the PCM data
 270  */
 271 static void deplanarize(LXFDemuxContext *lxf, AVStream *ast, uint8_t *out, int bytes)
 272 {
 273     int x, y, z, i, bytes_per_sample = ast->codec->bits_per_coded_sample >> 3;
 274
 275     for (z = i = 0; z < lxf->channels; z++)
 276         for (y = 0; y < bytes / bytes_per_sample / lxf->channels; y++)
 277             for (x = 0; x < bytes_per_sample; x++, i++)
 278                 out[x + bytes_per_sample*(z + y*lxf->channels)] = lxf->temp[i];
 279 }
 280
 281 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
 282 {
 283     LXFDemuxContext *lxf = s->priv_data;
 284     AVIOContext   *pb  = s->pb;
 285     uint8_t header[LXF_PACKET_HEADER_SIZE], *buf;
 286     AVStream *ast = NULL;
 287     uint32_t stream, format;
 288     int ret, ret2;
 289
 290     if ((ret = get_packet_header(s, header, &format)) < 0)
 291         return ret;
 292
 293     stream = AV_RL32(&header[16]);
 294
 295     if (stream > 1) {
 296         av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
 297         return AVERROR(EAGAIN);
 298     }
 299
 300     if (stream == 1 && !(ast = s->streams[1])) {
 301         av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
 302         return AVERROR_INVALIDDATA;
 303     }
 304
 305     //make sure the data fits in the de-planerization buffer
 306     if (ast && ret > LXF_MAX_AUDIO_PACKET) {
 307         av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
 308             ret, LXF_MAX_AUDIO_PACKET);
 309         return AVERROR_INVALIDDATA;
 310     }
 311
 312     if ((ret2 = av_new_packet(pkt, ret)) < 0)
 313         return ret2;
 314
 315     //read non-20-bit audio data into lxf->temp so we can deplanarize it
 316     buf = ast && ast->codec->codec_id != AV_CODEC_ID_PCM_LXF ? lxf->temp : pkt->data;
 317
 318     if ((ret2 = avio_read(pb, buf, ret)) != ret) {
 319         av_free_packet(pkt);
 320         return ret2 < 0 ? ret2 : AVERROR_EOF;
 321     }
 322
 323     pkt->stream_index = stream;
 324
 325     if (ast) {
 326         if(ast->codec->codec_id != AV_CODEC_ID_PCM_LXF)
 327             deplanarize(lxf, ast, pkt->data, ret);
 328     } else {
 329         //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
 330         if (((format >> 22) & 0x3) < 2)
 331             pkt->flags |= AV_PKT_FLAG_KEY;
 332
 333         pkt->dts = lxf->frame_number++;
 334     }
 335
 336     return ret;
 337 }
 338
 339 AVInputFormat ff_lxf_demuxer = {
 340     .name           = "lxf",
 341     .long_name      = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
 342     .priv_data_size = sizeof(LXFDemuxContext),
 343     .read_probe     = lxf_probe,
 344     .read_header    = lxf_read_header,
 345     .read_packet    = lxf_read_packet,
 346     .codec_tag      = (const AVCodecTag* const []){lxf_tags, 0},
 347 };