3 * Copyright (c) 2010 Tomas Härdin
5 * This file is part of Libav.
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.
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.
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
24 #include "libavutil/intreadwrite.h"
25 #include "libavcodec/bytestream.h"
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
35 static const AVCodecTag lxf_tags
[] = {
36 { AV_CODEC_ID_MJPEG
, 0 },
37 { AV_CODEC_ID_MPEG1VIDEO
, 1 },
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 },
49 typedef struct LXFDemuxContext
{
50 int channels
; ///< number of audio channels. zero means no audio
51 int frame_number
; ///< current video frame
52 uint32_t video_format
, packet_type
, extended_size
;
55 static int lxf_probe(AVProbeData
*p
)
57 if (!memcmp(p
->buf
, LXF_IDENT
, LXF_IDENT_LENGTH
))
58 return AVPROBE_SCORE_MAX
;
64 * Verify the checksum of an LXF packet header
66 * @param[in] header the packet header to check
67 * @return zero if the checksum is OK, non-zero otherwise
69 static int check_checksum(const uint8_t *header
, int size
)
74 for (x
= 0; x
< size
; x
+= 4)
75 sum
+= AV_RL32(&header
[x
]);
81 * Read input until we find the next ident. If found, copy it to the header buffer
83 * @param[out] header where to copy the ident to
84 * @return 0 if an ident was found, < 0 on I/O error
86 static int sync(AVFormatContext
*s
, uint8_t *header
)
88 uint8_t buf
[LXF_IDENT_LENGTH
];
91 if ((ret
= avio_read(s
->pb
, buf
, LXF_IDENT_LENGTH
)) != LXF_IDENT_LENGTH
)
92 return ret
< 0 ? ret
: AVERROR_EOF
;
94 while (memcmp(buf
, LXF_IDENT
, LXF_IDENT_LENGTH
)) {
95 if (s
->pb
->eof_reached
)
98 memmove(buf
, &buf
[1], LXF_IDENT_LENGTH
-1);
99 buf
[LXF_IDENT_LENGTH
-1] = avio_r8(s
->pb
);
102 memcpy(header
, LXF_IDENT
, LXF_IDENT_LENGTH
);
108 * Read and checksum the next packet header
110 * @return the size of the payload following the header or < 0 on failure
112 static int get_packet_header(AVFormatContext
*s
)
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
;
119 uint8_t header
[LXF_MAX_PACKET_HEADER_SIZE
];
120 const uint8_t *p
= header
+ LXF_IDENT_LENGTH
;
122 //find and read the ident
123 if ((ret
= sync(s
, header
)) < 0)
126 ret
= avio_read(pb
, header
+ LXF_IDENT_LENGTH
, 8);
128 return ret
< 0 ? ret
: AVERROR_EOF
;
130 version
= bytestream_get_le32(&p
);
131 header_size
= bytestream_get_le32(&p
);
133 avpriv_request_sample(s
, "Format version %"PRIu32
, version
);
135 if (header_size
< (version ?
72 : 60) ||
136 header_size
> LXF_MAX_PACKET_HEADER_SIZE
||
138 av_log(s
, AV_LOG_ERROR
, "Invalid header size 0x%"PRIx32
"\n", header_size
);
139 return AVERROR_INVALIDDATA
;
142 //read the rest of the packet header
143 ret
= avio_read(pb
, header
+ (p
- header
), header_size
- (p
- header
));
144 if (ret
!= header_size
- (p
- header
))
145 return ret
< 0 ? ret
: AVERROR_EOF
;
147 if (check_checksum(header
, header_size
))
148 av_log(s
, AV_LOG_ERROR
, "checksum error\n");
150 lxf
->packet_type
= bytestream_get_le32(&p
);
151 p
+= version ?
20 : 12;
153 lxf
->extended_size
= 0;
154 switch (lxf
->packet_type
) {
157 lxf
->video_format
= bytestream_get_le32(&p
);
158 ret
= bytestream_get_le32(&p
);
159 //skip VBI data and metadata
160 avio_skip(pb
, (int64_t)(uint32_t)AV_RL32(p
+ 4) +
161 (int64_t)(uint32_t)AV_RL32(p
+ 12));
165 if (s
->nb_streams
< 2) {
166 av_log(s
, AV_LOG_INFO
, "got audio packet, but no audio stream present\n");
172 audio_format
= bytestream_get_le32(&p
);
173 channels
= bytestream_get_le32(&p
);
174 track_size
= bytestream_get_le32(&p
);
178 //set codec based on specified audio bitdepth
179 //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
180 st
->codecpar
->bits_per_coded_sample
= (audio_format
>> 6) & 0x3F;
182 if (st
->codecpar
->bits_per_coded_sample
!= (audio_format
& 0x3F)) {
183 avpriv_report_missing_feature(s
, "Not tightly packed PCM");
184 return AVERROR_PATCHWELCOME
;
187 switch (st
->codecpar
->bits_per_coded_sample
) {
188 case 16: st
->codecpar
->codec_id
= AV_CODEC_ID_PCM_S16LE_PLANAR
; break;
189 case 20: st
->codecpar
->codec_id
= AV_CODEC_ID_PCM_LXF
; break;
190 case 24: st
->codecpar
->codec_id
= AV_CODEC_ID_PCM_S24LE_PLANAR
; break;
191 case 32: st
->codecpar
->codec_id
= AV_CODEC_ID_PCM_S32LE_PLANAR
; break;
193 avpriv_report_missing_feature(s
, "PCM not 16-, 20-, 24- or 32-bits");
194 return AVERROR_PATCHWELCOME
;
197 samples
= track_size
* 8 / st
->codecpar
->bits_per_coded_sample
;
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);
204 //assume PAL, but warn if we don't have 1920 samples
205 if (samples
!= LXF_SAMPLERATE
/ 25)
206 av_log(s
, AV_LOG_WARNING
,
207 "video doesn't seem to be PAL or NTSC. guessing PAL\n");
209 avpriv_set_pts_info(s
->streams
[0], 64, 1, 25);
212 //TODO: warning if track mask != (1 << channels) - 1?
213 ret
= av_popcount(channels
) * track_size
;
217 tmp
= bytestream_get_le32(&p
);
218 ret
= bytestream_get_le32(&p
);
220 lxf
->extended_size
= bytestream_get_le32(&p
);
227 static int lxf_read_header(AVFormatContext
*s
)
229 LXFDemuxContext
*lxf
= s
->priv_data
;
230 AVIOContext
*pb
= s
->pb
;
231 uint8_t header_data
[LXF_HEADER_DATA_SIZE
];
234 uint32_t video_params
, disk_params
;
235 uint16_t record_date
, expiration_date
;
237 if ((ret
= get_packet_header(s
)) < 0)
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
;
246 if ((ret
= avio_read(pb
, header_data
, LXF_HEADER_DATA_SIZE
)) != LXF_HEADER_DATA_SIZE
)
247 return ret
< 0 ? ret
: AVERROR_EOF
;
249 if (!(st
= avformat_new_stream(s
, NULL
)))
250 return AVERROR(ENOMEM
);
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]);
258 st
->codecpar
->codec_type
= AVMEDIA_TYPE_VIDEO
;
259 st
->codecpar
->bit_rate
= 1000000 * ((video_params
>> 14) & 0xFF);
260 st
->codecpar
->codec_tag
= video_params
& 0xF;
261 st
->codecpar
->codec_id
= ff_codec_get_id(lxf_tags
, st
->codecpar
->codec_tag
);
263 av_log(s
, AV_LOG_DEBUG
, "record: %x = %i-%02i-%02i\n",
264 record_date
, 1900 + (record_date
& 0x7F), (record_date
>> 7) & 0xF,
265 (record_date
>> 11) & 0x1F);
267 av_log(s
, AV_LOG_DEBUG
, "expire: %x = %i-%02i-%02i\n",
268 expiration_date
, 1900 + (expiration_date
& 0x7F), (expiration_date
>> 7) & 0xF,
269 (expiration_date
>> 11) & 0x1F);
271 if ((video_params
>> 22) & 1)
272 av_log(s
, AV_LOG_WARNING
, "VBI data not yet supported\n");
274 if ((lxf
->channels
= 1 << (disk_params
>> 4 & 3) + 1)) {
275 if (!(st
= avformat_new_stream(s
, NULL
)))
276 return AVERROR(ENOMEM
);
278 st
->codecpar
->codec_type
= AVMEDIA_TYPE_AUDIO
;
279 st
->codecpar
->sample_rate
= LXF_SAMPLERATE
;
280 st
->codecpar
->channels
= lxf
->channels
;
282 avpriv_set_pts_info(st
, 64, 1, st
->codecpar
->sample_rate
);
285 avio_skip(s
->pb
, lxf
->extended_size
);
290 static int lxf_read_packet(AVFormatContext
*s
, AVPacket
*pkt
)
292 LXFDemuxContext
*lxf
= s
->priv_data
;
293 AVIOContext
*pb
= s
->pb
;
297 if ((ret
= get_packet_header(s
)) < 0)
300 stream
= lxf
->packet_type
;
303 av_log(s
, AV_LOG_WARNING
,
304 "got packet with illegal stream index %"PRIu32
"\n", stream
);
305 return AVERROR(EAGAIN
);
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
;
313 if ((ret2
= av_new_packet(pkt
, ret
)) < 0)
316 if ((ret2
= avio_read(pb
, pkt
->data
, ret
)) != ret
) {
317 av_packet_unref(pkt
);
318 return ret2
< 0 ? ret2
: AVERROR_EOF
;
321 pkt
->stream_index
= 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
;
328 pkt
->dts
= lxf
->frame_number
++;
334 AVInputFormat ff_lxf_demuxer
= {
336 .long_name
= NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
337 .priv_data_size
= sizeof(LXFDemuxContext
),
338 .read_probe
= lxf_probe
,
339 .read_header
= lxf_read_header
,
340 .read_packet
= lxf_read_packet
,
341 .codec_tag
= (const AVCodecTag
* const []){lxf_tags
, 0},