Libav
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 "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;
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 
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 
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 
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  ret = avio_read(pb, header + (p - header), header_size - (p - header));
142  if (ret != header_size - (p - header))
143  return ret < 0 ? ret : AVERROR_EOF;
144 
145  if (check_checksum(header, header_size))
146  av_log(s, AV_LOG_ERROR, "checksum error\n");
147 
148  lxf->packet_type = bytestream_get_le32(&p);
149  p += version ? 20 : 12;
150 
151  lxf->extended_size = 0;
152  switch (lxf->packet_type) {
153  case 0:
154  //video
155  lxf->video_format = bytestream_get_le32(&p);
156  ret = bytestream_get_le32(&p);
157  //skip VBI data and metadata
158  avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
159  (int64_t)(uint32_t)AV_RL32(p + 12));
160  break;
161  case 1:
162  //audio
163  if (s->nb_streams < 2) {
164  av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
165  break;
166  }
167 
168  if (version == 0)
169  p += 8;
170  audio_format = bytestream_get_le32(&p);
171  channels = bytestream_get_le32(&p);
172  track_size = bytestream_get_le32(&p);
173 
174  st = s->streams[1];
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  uint32_t stream;
294  int ret, ret2;
295 
296  if ((ret = get_packet_header(s)) < 0)
297  return ret;
298 
299  stream = lxf->packet_type;
300 
301  if (stream > 1) {
302  av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
303  return AVERROR(EAGAIN);
304  }
305 
306  if (stream == 1 && s->nb_streams < 2) {
307  av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
308  return AVERROR_INVALIDDATA;
309  }
310 
311  if ((ret2 = av_new_packet(pkt, ret)) < 0)
312  return ret2;
313 
314  if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
315  av_free_packet(pkt);
316  return ret2 < 0 ? ret2 : AVERROR_EOF;
317  }
318 
319  pkt->stream_index = stream;
320 
321  if (!stream) {
322  //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
323  if (((lxf->video_format >> 22) & 0x3) < 2)
324  pkt->flags |= AV_PKT_FLAG_KEY;
325 
326  pkt->dts = lxf->frame_number++;
327  }
328 
329  return ret;
330 }
331 
333  .name = "lxf",
334  .long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
335  .priv_data_size = sizeof(LXFDemuxContext),
339  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
340 };
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
int size
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:242
int frame_number
current video frame
Definition: lxfdec.c:49
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2074
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:129
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:3208
static int sync(AVFormatContext *s, uint8_t *header)
Read input until we find the next ident.
Definition: lxfdec.c:84
#define AV_RL16
Definition: intreadwrite.h:42
static int check_checksum(const uint8_t *header, int size)
Verify the checksum of an LXF packet header.
Definition: lxfdec.c:67
static int16_t * samples
Definition: output.c:53
AVInputFormat ff_lxf_demuxer
Definition: lxfdec.c:332
int channels
number of audio channels. zero means no audio
Definition: lxfdec.c:48
Format I/O context.
Definition: avformat.h:871
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t
static int lxf_read_header(AVFormatContext *s)
Definition: lxfdec.c:226
#define LXF_IDENT
Definition: lxfdec.c:29
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:935
uint8_t * data
Definition: avcodec.h:973
#define AVERROR_EOF
End of file.
Definition: error.h:51
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2481
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:446
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1023
static int lxf_probe(AVProbeData *p)
Definition: lxfdec.c:53
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:80
uint32_t packet_type
Definition: lxfdec.c:50
#define LXF_IDENT_LENGTH
Definition: lxfdec.c:30
uint32_t video_format
Definition: lxfdec.c:50
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:142
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:144
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2662
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:979
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:437
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:702
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:390
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:923
int bit_rate
the average bitrate
Definition: avcodec.h:1112
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:210
#define AV_RL32
Definition: intreadwrite.h:146
preferred ID for MPEG-1/2 video decoding
Definition: avcodec.h:110
#define LXF_MAX_PACKET_HEADER_SIZE
Definition: lxfdec.c:27
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:536
Stream structure.
Definition: avformat.h:683
#define AVERROR_PATCHWELCOME
Not yet implemented in Libav, patches welcome.
Definition: error.h:57
#define LXF_HEADER_DATA_SIZE
Definition: lxfdec.c:28
NULL
Definition: eval.c:55
#define AV_LOG_INFO
Standard information.
Definition: log.h:134
uint32_t extended_size
Definition: lxfdec.c:50
enum AVMediaType codec_type
Definition: avcodec.h:1062
version
Definition: ffv1enc.c:1080
enum AVCodecID codec_id
Definition: avcodec.h:1065
int sample_rate
samples per second
Definition: avcodec.h:1779
AVIOContext * pb
I/O context.
Definition: avformat.h:913
static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: lxfdec.c:289
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1080
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
static int get_packet_header(AVFormatContext *s)
Read and checksum the next packet header.
Definition: lxfdec.c:110
This structure contains the data a format has to probe a file.
Definition: avformat.h:388
static const AVCodecTag lxf_tags[]
Definition: lxfdec.c:33
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:734
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:395
Main libavformat public API header.
int eof_reached
true if eof reached
Definition: avio.h:96
int channels
number of audio channels
Definition: avcodec.h:1780
void * priv_data
Format private data.
Definition: avformat.h:899
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:972
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:516
int stream_index
Definition: avcodec.h:975
This structure stores compressed data.
Definition: avcodec.h:950
#define LXF_SAMPLERATE
Definition: lxfdec.c:31