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 #include "riff.h"
26 
27 #define LXF_PACKET_HEADER_SIZE 60
28 #define LXF_HEADER_DATA_SIZE 120
29 #define LXF_IDENT "LEITCH\0"
30 #define LXF_IDENT_LENGTH 8
31 #define LXF_SAMPLERATE 48000
32 #define LXF_MAX_AUDIO_PACKET (8008*15*4)
33 
34 static const AVCodecTag lxf_tags[] = {
35  { CODEC_ID_MJPEG, 0 },
36  { CODEC_ID_MPEG1VIDEO, 1 },
37  { CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
38  { CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
39  { CODEC_ID_DVVIDEO, 4 }, //DV25
40  { CODEC_ID_DVVIDEO, 5 }, //DVCPRO
41  { CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
42  { CODEC_ID_RAWVIDEO, 7 }, //PIX_FMT_ARGB, where alpha is used for chroma keying
43  { CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
44  { CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
45  { CODEC_ID_NONE, 0 },
46 };
47 
48 typedef struct {
49  int channels;
50  uint8_t temp[LXF_MAX_AUDIO_PACKET];
53 
54 static int lxf_probe(AVProbeData *p)
55 {
56  if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
57  return AVPROBE_SCORE_MAX;
58 
59  return 0;
60 }
61 
68 static int check_checksum(const uint8_t *header)
69 {
70  int x;
71  uint32_t sum = 0;
72 
73  for (x = 0; x < LXF_PACKET_HEADER_SIZE; x += 4)
74  sum += AV_RL32(&header[x]);
75 
76  return sum;
77 }
78 
85 static int sync(AVFormatContext *s, uint8_t *header)
86 {
87  uint8_t buf[LXF_IDENT_LENGTH];
88  int ret;
89 
90  if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
91  return ret < 0 ? ret : AVERROR_EOF;
92 
93  while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
94  if (s->pb->eof_reached)
95  return AVERROR_EOF;
96 
97  memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
98  buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
99  }
100 
101  memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
102 
103  return 0;
104 }
105 
113 static int get_packet_header(AVFormatContext *s, uint8_t *header, uint32_t *format)
114 {
115  AVIOContext *pb = s->pb;
116  int track_size, samples, ret;
117  AVStream *st;
118 
119  //find and read the ident
120  if ((ret = sync(s, header)) < 0)
121  return ret;
122 
123  //read the rest of the packet header
124  if ((ret = avio_read(pb, header + LXF_IDENT_LENGTH,
127  return ret < 0 ? ret : AVERROR_EOF;
128  }
129 
130  if (check_checksum(header))
131  av_log(s, AV_LOG_ERROR, "checksum error\n");
132 
133  *format = AV_RL32(&header[32]);
134  ret = AV_RL32(&header[36]);
135 
136  //type
137  switch (AV_RL32(&header[16])) {
138  case 0:
139  //video
140  //skip VBI data and metadata
141  avio_skip(pb, (int64_t)(uint32_t)AV_RL32(&header[44]) +
142  (int64_t)(uint32_t)AV_RL32(&header[52]));
143  break;
144  case 1:
145  //audio
146  if (!(st = s->streams[1])) {
147  av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
148  break;
149  }
150 
151  //set codec based on specified audio bitdepth
152  //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
153  *format = AV_RL32(&header[40]);
154  st->codec->bits_per_coded_sample = (*format >> 6) & 0x3F;
155 
156  if (st->codec->bits_per_coded_sample != (*format & 0x3F)) {
157  av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
158  return AVERROR_PATCHWELCOME;
159  }
160 
161  switch (st->codec->bits_per_coded_sample) {
162  case 16: st->codec->codec_id = CODEC_ID_PCM_S16LE; break;
163  case 20: st->codec->codec_id = CODEC_ID_PCM_LXF; break;
164  case 24: st->codec->codec_id = CODEC_ID_PCM_S24LE; break;
165  case 32: st->codec->codec_id = CODEC_ID_PCM_S32LE; break;
166  default:
168  "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
169  return AVERROR_PATCHWELCOME;
170  }
171 
172  track_size = AV_RL32(&header[48]);
173  samples = track_size * 8 / st->codec->bits_per_coded_sample;
174 
175  //use audio packet size to determine video standard
176  //for NTSC we have one 8008-sample audio frame per five video frames
177  if (samples == LXF_SAMPLERATE * 5005 / 30000) {
178  avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
179  } else {
180  //assume PAL, but warn if we don't have 1920 samples
181  if (samples != LXF_SAMPLERATE / 25)
183  "video doesn't seem to be PAL or NTSC. guessing PAL\n");
184 
185  avpriv_set_pts_info(s->streams[0], 64, 1, 25);
186  }
187 
188  //TODO: warning if track mask != (1 << channels) - 1?
189  ret = av_popcount(AV_RL32(&header[44])) * track_size;
190 
191  break;
192  default:
193  break;
194  }
195 
196  return ret;
197 }
198 
200 {
201  LXFDemuxContext *lxf = s->priv_data;
202  AVIOContext *pb = s->pb;
203  uint8_t header[LXF_PACKET_HEADER_SIZE], header_data[LXF_HEADER_DATA_SIZE];
204  int ret;
205  AVStream *st;
206  uint32_t format, video_params, disk_params;
207  uint16_t record_date, expiration_date;
208 
209  if ((ret = get_packet_header(s, header, &format)) < 0)
210  return ret;
211 
212  if (ret != LXF_HEADER_DATA_SIZE) {
213  av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
214  LXF_HEADER_DATA_SIZE, ret);
215  return AVERROR_INVALIDDATA;
216  }
217 
218  if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
219  return ret < 0 ? ret : AVERROR_EOF;
220 
221  if (!(st = avformat_new_stream(s, NULL)))
222  return AVERROR(ENOMEM);
223 
224  st->duration = AV_RL32(&header_data[32]);
225  video_params = AV_RL32(&header_data[40]);
226  record_date = AV_RL16(&header_data[56]);
227  expiration_date = AV_RL16(&header_data[58]);
228  disk_params = AV_RL32(&header_data[116]);
229 
231  st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
232  st->codec->codec_tag = video_params & 0xF;
233  st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
234 
235  av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
236  record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
237  (record_date >> 11) & 0x1F);
238 
239  av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
240  expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
241  (expiration_date >> 11) & 0x1F);
242 
243  if ((video_params >> 22) & 1)
244  av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
245 
246  if ((lxf->channels = (disk_params >> 2) & 0xF)) {
247  if (!(st = avformat_new_stream(s, NULL)))
248  return AVERROR(ENOMEM);
249 
252  st->codec->channels = lxf->channels;
253 
254  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
255  }
256 
257  if (format == 1) {
258  //skip extended field data
259  avio_skip(s->pb, (uint32_t)AV_RL32(&header[40]));
260  }
261 
262  return 0;
263 }
264 
272 static void deplanarize(LXFDemuxContext *lxf, AVStream *ast, uint8_t *out, int bytes)
273 {
274  int x, y, z, i, bytes_per_sample = ast->codec->bits_per_coded_sample >> 3;
275 
276  for (z = i = 0; z < lxf->channels; z++)
277  for (y = 0; y < bytes / bytes_per_sample / lxf->channels; y++)
278  for (x = 0; x < bytes_per_sample; x++, i++)
279  out[x + bytes_per_sample*(z + y*lxf->channels)] = lxf->temp[i];
280 }
281 
283 {
284  LXFDemuxContext *lxf = s->priv_data;
285  AVIOContext *pb = s->pb;
286  uint8_t header[LXF_PACKET_HEADER_SIZE], *buf;
287  AVStream *ast = NULL;
288  uint32_t stream, format;
289  int ret, ret2;
290 
291  if ((ret = get_packet_header(s, header, &format)) < 0)
292  return ret;
293 
294  stream = AV_RL32(&header[16]);
295 
296  if (stream > 1) {
297  av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
298  return AVERROR(EAGAIN);
299  }
300 
301  if (stream == 1 && !(ast = s->streams[1])) {
302  av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
303  return AVERROR_INVALIDDATA;
304  }
305 
306  //make sure the data fits in the de-planerization buffer
307  if (ast && ret > LXF_MAX_AUDIO_PACKET) {
308  av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
309  ret, LXF_MAX_AUDIO_PACKET);
310  return AVERROR_INVALIDDATA;
311  }
312 
313  if ((ret2 = av_new_packet(pkt, ret)) < 0)
314  return ret2;
315 
316  //read non-20-bit audio data into lxf->temp so we can deplanarize it
317  buf = ast && ast->codec->codec_id != CODEC_ID_PCM_LXF ? lxf->temp : pkt->data;
318 
319  if ((ret2 = avio_read(pb, buf, ret)) != ret) {
320  av_free_packet(pkt);
321  return ret2 < 0 ? ret2 : AVERROR_EOF;
322  }
323 
324  pkt->stream_index = stream;
325 
326  if (ast) {
327  if(ast->codec->codec_id != CODEC_ID_PCM_LXF)
328  deplanarize(lxf, ast, pkt->data, ret);
329  } else {
330  //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
331  if (((format >> 22) & 0x3) < 2)
332  pkt->flags |= AV_PKT_FLAG_KEY;
333 
334  pkt->dts = lxf->frame_number++;
335  }
336 
337  return ret;
338 }
339 
341  .name = "lxf",
342  .long_name = NULL_IF_CONFIG_SMALL("VR native stream format (LXF)"),
343  .priv_data_size = sizeof(LXFDemuxContext),
347  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
348 };
349