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libavformat/lxfdec.c

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00001 /*
00002  * LXF demuxer
00003  * Copyright (c) 2010 Tomas Härdin
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 
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 (url_feof(s->pb))
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 

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