3 * Copyright (c) 2010 Tomas Härdin
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavutil/intreadwrite.h"
23 #include "libavcodec/bytestream.h"
28 #define LXF_MAX_PACKET_HEADER_SIZE 256
29 #define LXF_HEADER_DATA_SIZE 120
30 #define LXF_IDENT "LEITCH\0"
31 #define LXF_IDENT_LENGTH 8
32 #define LXF_SAMPLERATE 48000
33 #define LXF_MAX_AUDIO_PACKET (8008*15*4) ///< 15-channel 32-bit NTSC audio frame
35 static const AVCodecTag lxf_tags[] = {
36 { CODEC_ID_MJPEG, 0 },
37 { CODEC_ID_MPEG1VIDEO, 1 },
38 { CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
39 { CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
40 { CODEC_ID_DVVIDEO, 4 }, //DV25
41 { CODEC_ID_DVVIDEO, 5 }, //DVCPRO
42 { CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
43 { CODEC_ID_RAWVIDEO, 7 }, //PIX_FMT_ARGB, where alpha is used for chroma keying
44 { CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
45 { CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
50 int channels; ///< number of audio channels. zero means no audio
51 uint8_t temp[LXF_MAX_AUDIO_PACKET]; ///< temp buffer for de-planarizing the audio data
52 int frame_number; ///< current video frame
53 uint32_t video_format, packet_type, extended_size;
56 static int lxf_probe(AVProbeData *p)
58 if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
59 return AVPROBE_SCORE_MAX;
65 * Verify the checksum of an LXF packet header
67 * @param[in] header the packet header to check
68 * @return zero if the checksum is OK, non-zero otherwise
70 static int check_checksum(const uint8_t *header, int size)
75 for (x = 0; x < size; x += 4)
76 sum += AV_RL32(&header[x]);
82 * Read input until we find the next ident. If found, copy it to the header buffer
84 * @param[out] header where to copy the ident to
85 * @return 0 if an ident was found, < 0 on I/O error
87 static int sync(AVFormatContext *s, uint8_t *header)
89 uint8_t buf[LXF_IDENT_LENGTH];
92 if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
93 return ret < 0 ? ret : AVERROR_EOF;
95 while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
99 memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
100 buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
103 memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
109 * Read and checksum the next packet header
111 * @return the size of the payload following the header or < 0 on failure
113 static int get_packet_header(AVFormatContext *s)
115 LXFDemuxContext *lxf = s->priv_data;
116 AVIOContext *pb = s->pb;
117 int track_size, samples, ret;
118 uint32_t version, audio_format, header_size, channels, tmp;
120 uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
123 //find and read the ident
124 if ((ret = sync(s, header)) < 0)
127 ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
129 return ret < 0 ? ret : AVERROR_EOF;
131 p = header + LXF_IDENT_LENGTH;
132 version = bytestream_get_le32(&p);
133 header_size = bytestream_get_le32(&p);
135 av_log_ask_for_sample(s, "Unknown format version %i\n", version);
136 if (header_size < (version ? 72 : 60) ||
137 header_size > LXF_MAX_PACKET_HEADER_SIZE ||
139 av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
140 return AVERROR_INVALIDDATA;
143 //read the rest of the packet header
144 if ((ret = avio_read(pb, header + (p - header),
145 header_size - (p - header))) !=
146 header_size - (p - header)) {
147 return ret < 0 ? ret : AVERROR_EOF;
150 if (check_checksum(header, header_size))
151 av_log(s, AV_LOG_ERROR, "checksum error\n");
153 lxf->packet_type = bytestream_get_le32(&p);
154 p += version ? 20 : 12;
156 lxf->extended_size = 0;
157 switch (lxf->packet_type) {
160 lxf->video_format = bytestream_get_le32(&p);
161 ret = bytestream_get_le32(&p);
162 //skip VBI data and metadata
163 avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
164 (int64_t)(uint32_t)AV_RL32(p + 12));
168 if (!(st = s->streams[1])) {
169 av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
173 if (version == 0) p += 8;
174 audio_format = bytestream_get_le32(&p);
175 channels = bytestream_get_le32(&p);
176 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->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
182 if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
183 av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
184 return AVERROR_PATCHWELCOME;
187 switch (st->codec->bits_per_coded_sample) {
188 case 16: st->codec->codec_id = CODEC_ID_PCM_S16LE; break;
189 case 20: st->codec->codec_id = CODEC_ID_PCM_LXF; break;
190 case 24: st->codec->codec_id = CODEC_ID_PCM_S24LE; break;
191 case 32: st->codec->codec_id = CODEC_ID_PCM_S32LE; break;
193 av_log(s, AV_LOG_WARNING,
194 "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
195 return AVERROR_PATCHWELCOME;
198 samples = track_size * 8 / st->codec->bits_per_coded_sample;
200 //use audio packet size to determine video standard
201 //for NTSC we have one 8008-sample audio frame per five video frames
202 if (samples == LXF_SAMPLERATE * 5005 / 30000) {
203 avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
205 //assume PAL, but warn if we don't have 1920 samples
206 if (samples != LXF_SAMPLERATE / 25)
207 av_log(s, AV_LOG_WARNING,
208 "video doesn't seem to be PAL or NTSC. guessing PAL\n");
210 avpriv_set_pts_info(s->streams[0], 64, 1, 25);
213 //TODO: warning if track mask != (1 << channels) - 1?
214 ret = av_popcount(channels) * track_size;
218 tmp = bytestream_get_le32(&p);
219 ret = bytestream_get_le32(&p);
221 lxf->extended_size = bytestream_get_le32(&p);
228 static int lxf_read_header(AVFormatContext *s)
230 LXFDemuxContext *lxf = s->priv_data;
231 AVIOContext *pb = s->pb;
232 uint8_t header_data[LXF_HEADER_DATA_SIZE];
235 uint32_t video_params, disk_params;
236 uint16_t record_date, expiration_date;
238 if ((ret = get_packet_header(s)) < 0)
241 if (ret != LXF_HEADER_DATA_SIZE) {
242 av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
243 LXF_HEADER_DATA_SIZE, ret);
244 return AVERROR_INVALIDDATA;
247 if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
248 return ret < 0 ? ret : AVERROR_EOF;
250 if (!(st = avformat_new_stream(s, NULL)))
251 return AVERROR(ENOMEM);
253 st->duration = AV_RL32(&header_data[32]);
254 video_params = AV_RL32(&header_data[40]);
255 record_date = AV_RL16(&header_data[56]);
256 expiration_date = AV_RL16(&header_data[58]);
257 disk_params = AV_RL32(&header_data[116]);
259 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
260 st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
261 st->codec->codec_tag = video_params & 0xF;
262 st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
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);
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);
272 if ((video_params >> 22) & 1)
273 av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
275 if ((lxf->channels = (disk_params >> 2) & 0xF)) {
276 if (!(st = avformat_new_stream(s, NULL)))
277 return AVERROR(ENOMEM);
279 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
280 st->codec->sample_rate = LXF_SAMPLERATE;
281 st->codec->channels = lxf->channels;
283 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
286 avio_skip(s->pb, lxf->extended_size);
292 * De-planerize the PCM data in lxf->temp
293 * FIXME: remove this once support for planar audio is added to libavcodec
295 * @param[out] out where to write the de-planerized data to
296 * @param[in] bytes the total size of the PCM data
298 static void deplanarize(LXFDemuxContext *lxf, AVStream *ast, uint8_t *out, int bytes)
300 int x, y, z, i, bytes_per_sample = ast->codec->bits_per_coded_sample >> 3;
302 for (z = i = 0; z < lxf->channels; z++)
303 for (y = 0; y < bytes / bytes_per_sample / lxf->channels; y++)
304 for (x = 0; x < bytes_per_sample; x++, i++)
305 out[x + bytes_per_sample*(z + y*lxf->channels)] = lxf->temp[i];
308 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
310 LXFDemuxContext *lxf = s->priv_data;
311 AVIOContext *pb = s->pb;
313 AVStream *ast = NULL;
317 if ((ret = get_packet_header(s)) < 0)
320 stream = lxf->packet_type;
323 av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
324 return AVERROR(EAGAIN);
327 if (stream == 1 && !(ast = s->streams[1])) {
328 av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
329 return AVERROR_INVALIDDATA;
332 //make sure the data fits in the de-planerization buffer
333 if (ast && ret > LXF_MAX_AUDIO_PACKET) {
334 av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
335 ret, LXF_MAX_AUDIO_PACKET);
336 return AVERROR_INVALIDDATA;
339 if ((ret2 = av_new_packet(pkt, ret)) < 0)
342 //read non-20-bit audio data into lxf->temp so we can deplanarize it
343 buf = ast && ast->codec->codec_id != CODEC_ID_PCM_LXF ? lxf->temp : pkt->data;
345 if ((ret2 = avio_read(pb, buf, ret)) != ret) {
347 return ret2 < 0 ? ret2 : AVERROR_EOF;
350 pkt->stream_index = stream;
353 if(ast->codec->codec_id != CODEC_ID_PCM_LXF)
354 deplanarize(lxf, ast, pkt->data, ret);
356 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
357 if (((lxf->video_format >> 22) & 0x3) < 2)
358 pkt->flags |= AV_PKT_FLAG_KEY;
360 pkt->dts = lxf->frame_number++;
366 AVInputFormat ff_lxf_demuxer = {
368 .long_name = NULL_IF_CONFIG_SMALL("VR native stream format (LXF)"),
369 .priv_data_size = sizeof(LXFDemuxContext),
370 .read_probe = lxf_probe,
371 .read_header = lxf_read_header,
372 .read_packet = lxf_read_packet,
373 .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},