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lxfdec.c
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1 /*
2  * LXF demuxer
3  * Copyright (c) 2010 Tomas Härdin
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 "libavutil/intreadwrite.h"
23 #include "libavcodec/bytestream.h"
24 #include "avformat.h"
25 #include "internal.h"
26 
27 #define LXF_MAX_PACKET_HEADER_SIZE 256
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) ///< 15-channel 32-bit NTSC audio frame
33 
34 static const AVCodecTag lxf_tags[] = {
35  { AV_CODEC_ID_MJPEG, 0 },
37  { AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
38  { AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
39  { AV_CODEC_ID_DVVIDEO, 4 }, //DV25
40  { AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO
41  { AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
42  { AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
43  { AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
44  { AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
45  { AV_CODEC_ID_NONE, 0 },
46 };
47 
48 typedef struct {
49  int channels; ///< number of audio channels. zero means no audio
50  int frame_number; ///< current video frame
51  uint32_t video_format, packet_type, extended_size;
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 
62 /**
63  * Verify the checksum of an LXF packet header
64  *
65  * @param[in] header the packet header to check
66  * @return zero if the checksum is OK, non-zero otherwise
67  */
68 static int check_checksum(const uint8_t *header, int size)
69 {
70  int x;
71  uint32_t sum = 0;
72 
73  for (x = 0; x < size; x += 4)
74  sum += AV_RL32(&header[x]);
75 
76  return sum;
77 }
78 
79 /**
80  * Read input until we find the next ident. If found, copy it to the header buffer
81  *
82  * @param[out] header where to copy the ident to
83  * @return 0 if an ident was found, < 0 on I/O error
84  */
85 static int sync(AVFormatContext *s, uint8_t *header)
86 {
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 (url_feof(s->pb))
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 
106 /**
107  * Read and checksum the next packet header
108  *
109  * @return the size of the payload following the header or < 0 on failure
110  */
112 {
113  LXFDemuxContext *lxf = s->priv_data;
114  AVIOContext *pb = s->pb;
115  int track_size, samples, ret;
116  uint32_t version, audio_format, header_size, channels, tmp;
117  AVStream *st;
119  const uint8_t *p;
120 
121  //find and read the ident
122  if ((ret = sync(s, header)) < 0)
123  return ret;
124 
125  ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
126  if (ret != 8)
127  return ret < 0 ? ret : AVERROR_EOF;
128 
129  p = header + LXF_IDENT_LENGTH;
130  version = bytestream_get_le32(&p);
131  header_size = bytestream_get_le32(&p);
132  if (version > 1)
133  av_log_ask_for_sample(s, "Unknown format version %i\n", version);
134  if (header_size < (version ? 72 : 60) ||
135  header_size > LXF_MAX_PACKET_HEADER_SIZE ||
136  (header_size & 3)) {
137  av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
138  return AVERROR_INVALIDDATA;
139  }
140 
141  //read the rest of the packet header
142  if ((ret = avio_read(pb, header + (p - header),
143  header_size - (p - header))) !=
144  header_size - (p - header)) {
145  return ret < 0 ? ret : AVERROR_EOF;
146  }
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->streams || !(st = s->streams[1])) {
167  av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
168  break;
169  }
170 
171  if (version == 0) p += 8;
172  audio_format = bytestream_get_le32(&p);
173  channels = bytestream_get_le32(&p);
174  track_size = bytestream_get_le32(&p);
175 
176  //set codec based on specified audio bitdepth
177  //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
178  st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
179 
180  if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
181  av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
182  return AVERROR_PATCHWELCOME;
183  }
184 
185  switch (st->codec->bits_per_coded_sample) {
186  case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
187  case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF; break;
188  case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
189  case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
190  default:
192  "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
193  return AVERROR_PATCHWELCOME;
194  }
195 
196  samples = track_size * 8 / st->codec->bits_per_coded_sample;
197 
198  //use audio packet size to determine video standard
199  //for NTSC we have one 8008-sample audio frame per five video frames
200  if (samples == LXF_SAMPLERATE * 5005 / 30000) {
201  avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
202  } else {
203  //assume PAL, but warn if we don't have 1920 samples
204  if (samples != LXF_SAMPLERATE / 25)
206  "video doesn't seem to be PAL or NTSC. guessing PAL\n");
207 
208  avpriv_set_pts_info(s->streams[0], 64, 1, 25);
209  }
210 
211  //TODO: warning if track mask != (1 << channels) - 1?
212  ret = av_popcount(channels) * track_size;
213 
214  break;
215  default:
216  tmp = bytestream_get_le32(&p);
217  ret = bytestream_get_le32(&p);
218  if (tmp == 1)
219  lxf->extended_size = bytestream_get_le32(&p);
220  break;
221  }
222 
223  return ret;
224 }
225 
227 {
228  LXFDemuxContext *lxf = s->priv_data;
229  AVIOContext *pb = s->pb;
230  uint8_t header_data[LXF_HEADER_DATA_SIZE];
231  int ret;
232  AVStream *st;
233  uint32_t video_params, disk_params;
234  uint16_t record_date, expiration_date;
235 
236  if ((ret = get_packet_header(s)) < 0)
237  return ret;
238 
239  if (ret != LXF_HEADER_DATA_SIZE) {
240  av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
241  LXF_HEADER_DATA_SIZE, ret);
242  return AVERROR_INVALIDDATA;
243  }
244 
245  if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
246  return ret < 0 ? ret : AVERROR_EOF;
247 
248  if (!(st = avformat_new_stream(s, NULL)))
249  return AVERROR(ENOMEM);
250 
251  st->duration = AV_RL32(&header_data[32]);
252  video_params = AV_RL32(&header_data[40]);
253  record_date = AV_RL16(&header_data[56]);
254  expiration_date = AV_RL16(&header_data[58]);
255  disk_params = AV_RL32(&header_data[116]);
256 
258  st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
259  st->codec->codec_tag = video_params & 0xF;
260  st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
261 
262  av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
263  record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
264  (record_date >> 11) & 0x1F);
265 
266  av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
267  expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
268  (expiration_date >> 11) & 0x1F);
269 
270  if ((video_params >> 22) & 1)
271  av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
272 
273  if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
274  if (!(st = avformat_new_stream(s, NULL)))
275  return AVERROR(ENOMEM);
276 
279  st->codec->channels = lxf->channels;
280 
281  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
282  }
283 
284  avio_skip(s->pb, lxf->extended_size);
285 
286  return 0;
287 }
288 
290 {
291  LXFDemuxContext *lxf = s->priv_data;
292  AVIOContext *pb = s->pb;
293  AVStream *ast = NULL;
294  uint32_t stream;
295  int ret, ret2;
296 
297  if ((ret = get_packet_header(s)) < 0)
298  return ret;
299 
300  stream = lxf->packet_type;
301 
302  if (stream > 1) {
303  av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
304  return AVERROR(EAGAIN);
305  }
306 
307  if (stream == 1 && !(ast = s->streams[1])) {
308  av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
309  return AVERROR_INVALIDDATA;
310  }
311 
312  //make sure the data fits in the de-planerization buffer
313  if (ast && ret > LXF_MAX_AUDIO_PACKET) {
314  av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
315  ret, LXF_MAX_AUDIO_PACKET);
316  return AVERROR_INVALIDDATA;
317  }
318 
319  if ((ret2 = av_new_packet(pkt, ret)) < 0)
320  return ret2;
321 
322  if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
323  av_free_packet(pkt);
324  return ret2 < 0 ? ret2 : AVERROR_EOF;
325  }
326 
327  pkt->stream_index = stream;
328 
329  if (!ast) {
330  //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
331  if (((lxf->video_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 (LXF)"),
343  .priv_data_size = sizeof(LXFDemuxContext),
347  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
348 };