FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
lxfdec.c
Go to the documentation of this file.
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 <inttypes.h>
23 
24 #include "libavutil/intreadwrite.h"
25 #include "libavcodec/bytestream.h"
26 #include "avformat.h"
27 #include "internal.h"
28 
29 #define LXF_MAX_PACKET_HEADER_SIZE 256
30 #define LXF_HEADER_DATA_SIZE 120
31 #define LXF_IDENT "LEITCH\0"
32 #define LXF_IDENT_LENGTH 8
33 #define LXF_SAMPLERATE 48000
34 
35 static const AVCodecTag lxf_tags[] = {
36  { AV_CODEC_ID_MJPEG, 0 },
38  { AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
39  { AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
40  { AV_CODEC_ID_DVVIDEO, 4 }, //DV25
41  { AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO
42  { AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
43  { AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
44  { AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
45  { AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
46  { AV_CODEC_ID_NONE, 0 },
47 };
48 
49 typedef struct LXFDemuxContext {
50  int channels; ///< number of audio channels. zero means no audio
51  int frame_number; ///< current video frame
54 
55 static int lxf_probe(AVProbeData *p)
56 {
57  if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
58  return AVPROBE_SCORE_MAX;
59 
60  return 0;
61 }
62 
63 /**
64  * Verify the checksum of an LXF packet header
65  *
66  * @param[in] header the packet header to check
67  * @return zero if the checksum is OK, non-zero otherwise
68  */
69 static int check_checksum(const uint8_t *header, int size)
70 {
71  int x;
72  uint32_t sum = 0;
73 
74  for (x = 0; x < size; x += 4)
75  sum += AV_RL32(&header[x]);
76 
77  return sum;
78 }
79 
80 /**
81  * Read input until we find the next ident. If found, copy it to the header buffer
82  *
83  * @param[out] header where to copy the ident to
84  * @return 0 if an ident was found, < 0 on I/O error
85  */
87 {
89  int ret;
90 
91  if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
92  return ret < 0 ? ret : AVERROR_EOF;
93 
94  while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
95  if (avio_feof(s->pb))
96  return AVERROR_EOF;
97 
98  memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
99  buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
100  }
101 
102  memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
103 
104  return 0;
105 }
106 
107 /**
108  * Read and checksum the next packet header
109  *
110  * @return the size of the payload following the header or < 0 on failure
111  */
113 {
114  LXFDemuxContext *lxf = s->priv_data;
115  AVIOContext *pb = s->pb;
116  int track_size, samples, ret;
117  uint32_t version, audio_format, header_size, channels, tmp;
118  AVStream *st;
120  const uint8_t *p = header + LXF_IDENT_LENGTH;
121 
122  //find and read the ident
123  if ((ret = lxf_sync(s, header)) < 0)
124  return ret;
125 
126  ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
127  if (ret != 8)
128  return ret < 0 ? ret : AVERROR_EOF;
129 
130  version = bytestream_get_le32(&p);
131  header_size = bytestream_get_le32(&p);
132  if (version > 1)
133  avpriv_request_sample(s, "Format version %"PRIu32, version);
134 
135  if (header_size < (version ? 72 : 60) ||
136  header_size > LXF_MAX_PACKET_HEADER_SIZE ||
137  (header_size & 3)) {
138  av_log(s, AV_LOG_ERROR, "Invalid header size 0x%"PRIx32"\n", header_size);
139  return AVERROR_INVALIDDATA;
140  }
141 
142  //read the rest of the packet header
143  if ((ret = avio_read(pb, header + (p - header),
144  header_size - (p - header))) !=
145  header_size - (p - header))
146  return ret < 0 ? ret : AVERROR_EOF;
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->nb_streams < 2) {
167  av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
168  break;
169  }
170 
171  if (version == 0)
172  p += 8;
173  audio_format = bytestream_get_le32(&p);
174  channels = bytestream_get_le32(&p);
175  track_size = bytestream_get_le32(&p);
176 
177  st = s->streams[1];
178 
179  //set codec based on specified audio bitdepth
180  //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
181  st->codecpar->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
182 
183  if (st->codecpar->bits_per_coded_sample != (audio_format & 0x3F)) {
184  av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
185  return AVERROR_PATCHWELCOME;
186  }
187 
188  switch (st->codecpar->bits_per_coded_sample) {
189  case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
190  case 20: st->codecpar->codec_id = AV_CODEC_ID_PCM_LXF; break;
191  case 24: st->codecpar->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
192  case 32: st->codecpar->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
193  default:
195  "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
196  return AVERROR_PATCHWELCOME;
197  }
198 
199  samples = track_size * 8 / st->codecpar->bits_per_coded_sample;
200 
201  //use audio packet size to determine video standard
202  //for NTSC we have one 8008-sample audio frame per five video frames
203  if (samples == LXF_SAMPLERATE * 5005 / 30000) {
204  avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
205  } else {
206  //assume PAL, but warn if we don't have 1920 samples
207  if (samples != LXF_SAMPLERATE / 25)
209  "video doesn't seem to be PAL or NTSC. guessing PAL\n");
210 
211  avpriv_set_pts_info(s->streams[0], 64, 1, 25);
212  }
213 
214  //TODO: warning if track mask != (1 << channels) - 1?
215  ret = av_popcount(channels) * track_size;
216 
217  break;
218  default:
219  tmp = bytestream_get_le32(&p);
220  ret = bytestream_get_le32(&p);
221  if (tmp == 1)
222  lxf->extended_size = bytestream_get_le32(&p);
223  break;
224  }
225 
226  return ret;
227 }
228 
230 {
231  LXFDemuxContext *lxf = s->priv_data;
232  AVIOContext *pb = s->pb;
233  uint8_t header_data[LXF_HEADER_DATA_SIZE];
234  int ret;
235  AVStream *st;
236  uint32_t video_params, disk_params;
237  uint16_t record_date, expiration_date;
238 
239  if ((ret = get_packet_header(s)) < 0)
240  return ret;
241 
242  if (ret != LXF_HEADER_DATA_SIZE) {
243  av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
244  LXF_HEADER_DATA_SIZE, ret);
245  return AVERROR_INVALIDDATA;
246  }
247 
248  if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
249  return ret < 0 ? ret : AVERROR_EOF;
250 
251  if (!(st = avformat_new_stream(s, NULL)))
252  return AVERROR(ENOMEM);
253 
254  st->duration = AV_RL32(&header_data[32]);
255  video_params = AV_RL32(&header_data[40]);
256  record_date = AV_RL16(&header_data[56]);
257  expiration_date = AV_RL16(&header_data[58]);
258  disk_params = AV_RL32(&header_data[116]);
259 
261  st->codecpar->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
262  st->codecpar->codec_tag = video_params & 0xF;
263  st->codecpar->codec_id = ff_codec_get_id(lxf_tags, st->codecpar->codec_tag);
265 
266  av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
267  record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
268  (record_date >> 11) & 0x1F);
269 
270  av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
271  expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
272  (expiration_date >> 11) & 0x1F);
273 
274  if ((video_params >> 22) & 1)
275  av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
276 
277  if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
278  if (!(st = avformat_new_stream(s, NULL)))
279  return AVERROR(ENOMEM);
280 
283  st->codecpar->channels = lxf->channels;
284 
285  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
286  }
287 
288  avio_skip(s->pb, lxf->extended_size);
289 
290  return 0;
291 }
292 
294 {
295  LXFDemuxContext *lxf = s->priv_data;
296  AVIOContext *pb = s->pb;
297  uint32_t stream;
298  int ret, ret2;
299 
300  if ((ret = get_packet_header(s)) < 0)
301  return ret;
302 
303  stream = lxf->packet_type;
304 
305  if (stream > 1) {
307  "got packet with illegal stream index %"PRIu32"\n", stream);
308  return FFERROR_REDO;
309  }
310 
311  if (stream == 1 && s->nb_streams < 2) {
312  av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
313  return AVERROR_INVALIDDATA;
314  }
315 
316  if ((ret2 = av_new_packet(pkt, ret)) < 0)
317  return ret2;
318 
319  if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
320  av_packet_unref(pkt);
321  return ret2 < 0 ? ret2 : AVERROR_EOF;
322  }
323 
324  pkt->stream_index = stream;
325 
326  if (!stream) {
327  //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
328  if (((lxf->video_format >> 22) & 0x3) < 2)
329  pkt->flags |= AV_PKT_FLAG_KEY;
330 
331  pkt->dts = lxf->frame_number++;
332  }
333 
334  return ret;
335 }
336 
338  .name = "lxf",
339  .long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
340  .priv_data_size = sizeof(LXFDemuxContext),
344  .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
345 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int frame_number
current video frame
Definition: lxfdec.c:51
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2944
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static int lxf_sync(AVFormatContext *s, uint8_t *header)
Read input until we find the next ident.
Definition: lxfdec.c:86
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:4405
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3915
static int check_checksum(const uint8_t *header, int size)
Verify the checksum of an LXF packet header.
Definition: lxfdec.c:69
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:287
int version
Definition: avisynth_c.h:629
static AVPacket pkt
AVInputFormat ff_lxf_demuxer
Definition: lxfdec.c:337
int channels
number of audio channels. zero means no audio
Definition: lxfdec.c:50
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1319
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
enum AVStreamParseType need_parsing
Definition: avformat.h:1074
static int lxf_read_header(AVFormatContext *s)
Definition: lxfdec.c:229
#define LXF_IDENT
Definition: lxfdec.c:31
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4043
#define FFERROR_REDO
Returned by demuxers to indicate that data was consumed but discarded (ignored streams or junk data)...
Definition: internal.h:562
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1387
uint8_t * data
Definition: avcodec.h:1577
#define AVERROR_EOF
End of file.
Definition: error.h:55
ptrdiff_t size
Definition: opengl_enc.c:101
static const uint8_t header[24]
Definition: sdr2.c:67
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:550
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3944
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1609
static int lxf_probe(AVProbeData *p)
Definition: lxfdec.c:55
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
uint32_t packet_type
Definition: lxfdec.c:52
#define LXF_IDENT_LENGTH
Definition: lxfdec.c:32
uint32_t video_format
Definition: lxfdec.c:52
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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:176
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3911
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1583
Only parse headers, do not repack.
Definition: avformat.h:807
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:541
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1375
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static uint8_t tmp[8]
Definition: des-test.c:38
preferred ID for MPEG-1/2 video decoding
Definition: avcodec.h:194
#define LXF_MAX_PACKET_HEADER_SIZE
Definition: lxfdec.c:29
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:638
Stream structure.
Definition: avformat.h:876
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define LXF_HEADER_DATA_SIZE
Definition: lxfdec.c:30
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
uint32_t extended_size
Definition: lxfdec.c:52
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:549
static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: lxfdec.c:293
void * buf
Definition: avisynth_c.h:553
static int get_packet_header(AVFormatContext *s)
Read and checksum the next packet header.
Definition: lxfdec.c:112
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
static const AVCodecTag lxf_tags[]
Definition: lxfdec.c:35
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4025
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
Main libavformat public API header.
void * priv_data
Format private data.
Definition: avformat.h:1347
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3957
int channels
Audio only.
Definition: avcodec.h:4021
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1576
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:311
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3919
int stream_index
Definition: avcodec.h:1579
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1554
#define LXF_SAMPLERATE
Definition: lxfdec.c:33