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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 
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; ///< number of audio channels. zero means no audio
49  int frame_number; ///< current video frame
50  uint32_t video_format, packet_type, extended_size;
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, int size)
68 {
69  int x;
70  uint32_t sum = 0;
71 
72  for (x = 0; x < 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 {
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 (url_feof(s->pb))
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  * @return the size of the payload following the header or < 0 on failure
109  */
111 {
112  LXFDemuxContext *lxf = s->priv_data;
113  AVIOContext *pb = s->pb;
114  int track_size, samples, ret;
115  uint32_t version, audio_format, header_size, channels, tmp;
116  AVStream *st;
118  const uint8_t *p = header + LXF_IDENT_LENGTH;
119 
120  //find and read the ident
121  if ((ret = sync(s, header)) < 0)
122  return ret;
123 
124  ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
125  if (ret != 8)
126  return ret < 0 ? ret : AVERROR_EOF;
127 
128  version = bytestream_get_le32(&p);
129  header_size = bytestream_get_le32(&p);
130  if (version > 1)
131  avpriv_request_sample(s, "Unknown format version %i\n", version);
132 
133  if (header_size < (version ? 72 : 60) ||
134  header_size > LXF_MAX_PACKET_HEADER_SIZE ||
135  (header_size & 3)) {
136  av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
137  return AVERROR_INVALIDDATA;
138  }
139 
140  //read the rest of the packet header
141  if ((ret = avio_read(pb, header + (p - header),
142  header_size - (p - header))) !=
143  header_size - (p - header))
144  return ret < 0 ? ret : AVERROR_EOF;
145 
146  if (check_checksum(header, header_size))
147  av_log(s, AV_LOG_ERROR, "checksum error\n");
148 
149  lxf->packet_type = bytestream_get_le32(&p);
150  p += version ? 20 : 12;
151 
152  lxf->extended_size = 0;
153  switch (lxf->packet_type) {
154  case 0:
155  //video
156  lxf->video_format = bytestream_get_le32(&p);
157  ret = bytestream_get_le32(&p);
158  //skip VBI data and metadata
159  avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
160  (int64_t)(uint32_t)AV_RL32(p + 12));
161  break;
162  case 1:
163  //audio
164  if (s->nb_streams < 2) {
165  av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
166  break;
167  }
168 
169  if (version == 0)
170  p += 8;
171  audio_format = bytestream_get_le32(&p);
172  channels = bytestream_get_le32(&p);
173  track_size = bytestream_get_le32(&p);
174 
175  st = s->streams[1];
176 
177  //set codec based on specified audio bitdepth
178  //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
179  st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
180 
181  if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
182  av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
183  return AVERROR_PATCHWELCOME;
184  }
185 
186  switch (st->codec->bits_per_coded_sample) {
187  case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
188  case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF; break;
189  case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
190  case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
191  default:
193  "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
194  return AVERROR_PATCHWELCOME;
195  }
196 
197  samples = track_size * 8 / st->codec->bits_per_coded_sample;
198 
199  //use audio packet size to determine video standard
200  //for NTSC we have one 8008-sample audio frame per five video frames
201  if (samples == LXF_SAMPLERATE * 5005 / 30000) {
202  avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
203  } else {
204  //assume PAL, but warn if we don't have 1920 samples
205  if (samples != LXF_SAMPLERATE / 25)
207  "video doesn't seem to be PAL or NTSC. guessing PAL\n");
208 
209  avpriv_set_pts_info(s->streams[0], 64, 1, 25);
210  }
211 
212  //TODO: warning if track mask != (1 << channels) - 1?
213  ret = av_popcount(channels) * track_size;
214 
215  break;
216  default:
217  tmp = bytestream_get_le32(&p);
218  ret = bytestream_get_le32(&p);
219  if (tmp == 1)
220  lxf->extended_size = bytestream_get_le32(&p);
221  break;
222  }
223 
224  return ret;
225 }
226 
228 {
229  LXFDemuxContext *lxf = s->priv_data;
230  AVIOContext *pb = s->pb;
231  uint8_t header_data[LXF_HEADER_DATA_SIZE];
232  int ret;
233  AVStream *st;
234  uint32_t video_params, disk_params;
235  uint16_t record_date, expiration_date;
236 
237  if ((ret = get_packet_header(s)) < 0)
238  return ret;
239 
240  if (ret != LXF_HEADER_DATA_SIZE) {
241  av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
242  LXF_HEADER_DATA_SIZE, ret);
243  return AVERROR_INVALIDDATA;
244  }
245 
246  if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
247  return ret < 0 ? ret : AVERROR_EOF;
248 
249  if (!(st = avformat_new_stream(s, NULL)))
250  return AVERROR(ENOMEM);
251 
252  st->duration = AV_RL32(&header_data[32]);
253  video_params = AV_RL32(&header_data[40]);
254  record_date = AV_RL16(&header_data[56]);
255  expiration_date = AV_RL16(&header_data[58]);
256  disk_params = AV_RL32(&header_data[116]);
257 
259  st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
260  st->codec->codec_tag = video_params & 0xF;
261  st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
263 
264  av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
265  record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
266  (record_date >> 11) & 0x1F);
267 
268  av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
269  expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
270  (expiration_date >> 11) & 0x1F);
271 
272  if ((video_params >> 22) & 1)
273  av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
274 
275  if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
276  if (!(st = avformat_new_stream(s, NULL)))
277  return AVERROR(ENOMEM);
278 
281  st->codec->channels = lxf->channels;
282 
283  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
284  }
285 
286  avio_skip(s->pb, lxf->extended_size);
287 
288  return 0;
289 }
290 
292 {
293  LXFDemuxContext *lxf = s->priv_data;
294  AVIOContext *pb = s->pb;
295  uint32_t stream;
296  int ret, ret2;
297 
298  if ((ret = get_packet_header(s)) < 0)
299  return ret;
300 
301  stream = lxf->packet_type;
302 
303  if (stream > 1) {
304  av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
305  return AVERROR(EAGAIN);
306  }
307 
308  if (stream == 1 && s->nb_streams < 2) {
309  av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
310  return AVERROR_INVALIDDATA;
311  }
312 
313  if ((ret2 = av_new_packet(pkt, ret)) < 0)
314  return ret2;
315 
316  if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
317  av_free_packet(pkt);
318  return ret2 < 0 ? ret2 : AVERROR_EOF;
319  }
320 
321  pkt->stream_index = stream;
322 
323  if (!stream) {
324  //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
325  if (((lxf->video_format >> 22) & 0x3) < 2)
326  pkt->flags |= AV_PKT_FLAG_KEY;
327 
328  pkt->dts = lxf->frame_number++;
329  }
330 
331  return ret;
332 }
333 
335  .name = "lxf",
336  .long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
337  .priv_data_size = sizeof(LXFDemuxContext),
341  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
342 };