lxfdec.c
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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)
32 
33 static const AVCodecTag lxf_tags[] = {
34  { AV_CODEC_ID_MJPEG, 0 },
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;
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 
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 
84 static int sync(AVFormatContext *s, uint8_t *header)
85 {
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 
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,
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:
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)
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 
199 {
200  LXFDemuxContext *lxf = s->priv_data;
201  AVIOContext *pb = s->pb;
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 
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 
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 
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 
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 
340  .name = "lxf",
341  .long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
342  .priv_data_size = sizeof(LXFDemuxContext),
346  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
347 };