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
22 #include "libavutil/intreadwrite.h"
27 #define LXF_PACKET_HEADER_SIZE 60
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 #define LXF_MAX_AUDIO_PACKET (8008*15*4) ///< 15-channel 32-bit NTSC audio frame
34 static const AVCodecTag lxf_tags[] = {
35 { CODEC_ID_MJPEG, 0 },
36 { CODEC_ID_MPEG1VIDEO, 1 },
37 { CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
38 { CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
39 { CODEC_ID_DVVIDEO, 4 }, //DV25
40 { CODEC_ID_DVVIDEO, 5 }, //DVCPRO
41 { CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
42 { CODEC_ID_RAWVIDEO, 7 }, //PIX_FMT_ARGB, where alpha is used for chroma keying
43 { CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
44 { CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
49 int channels; ///< number of audio channels. zero means no audio
50 uint8_t temp[LXF_MAX_AUDIO_PACKET]; ///< temp buffer for de-planarizing the audio data
51 int frame_number; ///< current video frame
54 static int lxf_probe(AVProbeData *p)
56 if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
57 return AVPROBE_SCORE_MAX;
63 * Verify the checksum of an LXF packet header
65 * @param[in] header the packet header to check
66 * @return zero if the checksum is OK, non-zero otherwise
68 static int check_checksum(const uint8_t *header)
73 for (x = 0; x < LXF_PACKET_HEADER_SIZE; x += 4)
74 sum += AV_RL32(&header[x]);
80 * Read input until we find the next ident. If found, copy it to the header buffer
82 * @param[out] header where to copy the ident to
83 * @return 0 if an ident was found, < 0 on I/O error
85 static int sync(AVFormatContext *s, uint8_t *header)
87 uint8_t buf[LXF_IDENT_LENGTH];
90 if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
91 return ret < 0 ? ret : AVERROR_EOF;
93 while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
94 if (s->pb->eof_reached)
97 memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
98 buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
101 memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
107 * Read and checksum the next packet header
109 * @param[out] header the read packet header
110 * @param[out] format context dependent format information
111 * @return the size of the payload following the header or < 0 on failure
113 static int get_packet_header(AVFormatContext *s, uint8_t *header, uint32_t *format)
115 AVIOContext *pb = s->pb;
116 int track_size, samples, ret;
119 //find and read the ident
120 if ((ret = sync(s, header)) < 0)
123 //read the rest of the packet header
124 if ((ret = avio_read(pb, header + LXF_IDENT_LENGTH,
125 LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH)) !=
126 LXF_PACKET_HEADER_SIZE - LXF_IDENT_LENGTH) {
127 return ret < 0 ? ret : AVERROR_EOF;
130 if (check_checksum(header))
131 av_log(s, AV_LOG_ERROR, "checksum error\n");
133 *format = AV_RL32(&header[32]);
134 ret = AV_RL32(&header[36]);
137 switch (AV_RL32(&header[16])) {
140 //skip VBI data and metadata
141 avio_skip(pb, (int64_t)(uint32_t)AV_RL32(&header[44]) +
142 (int64_t)(uint32_t)AV_RL32(&header[52]));
146 if (!(st = s->streams[1])) {
147 av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
151 //set codec based on specified audio bitdepth
152 //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
153 *format = AV_RL32(&header[40]);
154 st->codec->bits_per_coded_sample = (*format >> 6) & 0x3F;
156 if (st->codec->bits_per_coded_sample != (*format & 0x3F)) {
157 av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
158 return AVERROR_PATCHWELCOME;
161 switch (st->codec->bits_per_coded_sample) {
162 case 16: st->codec->codec_id = CODEC_ID_PCM_S16LE; break;
163 case 20: st->codec->codec_id = CODEC_ID_PCM_LXF; break;
164 case 24: st->codec->codec_id = CODEC_ID_PCM_S24LE; break;
165 case 32: st->codec->codec_id = CODEC_ID_PCM_S32LE; break;
167 av_log(s, AV_LOG_WARNING,
168 "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
169 return AVERROR_PATCHWELCOME;
172 track_size = AV_RL32(&header[48]);
173 samples = track_size * 8 / st->codec->bits_per_coded_sample;
175 //use audio packet size to determine video standard
176 //for NTSC we have one 8008-sample audio frame per five video frames
177 if (samples == LXF_SAMPLERATE * 5005 / 30000) {
178 avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
180 //assume PAL, but warn if we don't have 1920 samples
181 if (samples != LXF_SAMPLERATE / 25)
182 av_log(s, AV_LOG_WARNING,
183 "video doesn't seem to be PAL or NTSC. guessing PAL\n");
185 avpriv_set_pts_info(s->streams[0], 64, 1, 25);
188 //TODO: warning if track mask != (1 << channels) - 1?
189 ret = av_popcount(AV_RL32(&header[44])) * track_size;
199 static int lxf_read_header(AVFormatContext *s, AVFormatParameters *ap)
201 LXFDemuxContext *lxf = s->priv_data;
202 AVIOContext *pb = s->pb;
203 uint8_t header[LXF_PACKET_HEADER_SIZE], header_data[LXF_HEADER_DATA_SIZE];
206 uint32_t format, video_params, disk_params;
207 uint16_t record_date, expiration_date;
209 if ((ret = get_packet_header(s, header, &format)) < 0)
212 if (ret != LXF_HEADER_DATA_SIZE) {
213 av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
214 LXF_HEADER_DATA_SIZE, ret);
215 return AVERROR_INVALIDDATA;
218 if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
219 return ret < 0 ? ret : AVERROR_EOF;
221 if (!(st = avformat_new_stream(s, NULL)))
222 return AVERROR(ENOMEM);
224 st->duration = AV_RL32(&header_data[32]);
225 video_params = AV_RL32(&header_data[40]);
226 record_date = AV_RL16(&header_data[56]);
227 expiration_date = AV_RL16(&header_data[58]);
228 disk_params = AV_RL32(&header_data[116]);
230 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
231 st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
232 st->codec->codec_tag = video_params & 0xF;
233 st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
235 av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
236 record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
237 (record_date >> 11) & 0x1F);
239 av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
240 expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
241 (expiration_date >> 11) & 0x1F);
243 if ((video_params >> 22) & 1)
244 av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
246 if ((lxf->channels = (disk_params >> 2) & 0xF)) {
247 if (!(st = avformat_new_stream(s, NULL)))
248 return AVERROR(ENOMEM);
250 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
251 st->codec->sample_rate = LXF_SAMPLERATE;
252 st->codec->channels = lxf->channels;
254 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
258 //skip extended field data
259 avio_skip(s->pb, (uint32_t)AV_RL32(&header[40]));
266 * De-planerize the PCM data in lxf->temp
267 * FIXME: remove this once support for planar audio is added to libavcodec
269 * @param[out] out where to write the de-planerized data to
270 * @param[in] bytes the total size of the PCM data
272 static void deplanarize(LXFDemuxContext *lxf, AVStream *ast, uint8_t *out, int bytes)
274 int x, y, z, i, bytes_per_sample = ast->codec->bits_per_coded_sample >> 3;
276 for (z = i = 0; z < lxf->channels; z++)
277 for (y = 0; y < bytes / bytes_per_sample / lxf->channels; y++)
278 for (x = 0; x < bytes_per_sample; x++, i++)
279 out[x + bytes_per_sample*(z + y*lxf->channels)] = lxf->temp[i];
282 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
284 LXFDemuxContext *lxf = s->priv_data;
285 AVIOContext *pb = s->pb;
286 uint8_t header[LXF_PACKET_HEADER_SIZE], *buf;
287 AVStream *ast = NULL;
288 uint32_t stream, format;
291 if ((ret = get_packet_header(s, header, &format)) < 0)
294 stream = AV_RL32(&header[16]);
297 av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
298 return AVERROR(EAGAIN);
301 if (stream == 1 && !(ast = s->streams[1])) {
302 av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
303 return AVERROR_INVALIDDATA;
306 //make sure the data fits in the de-planerization buffer
307 if (ast && ret > LXF_MAX_AUDIO_PACKET) {
308 av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
309 ret, LXF_MAX_AUDIO_PACKET);
310 return AVERROR_INVALIDDATA;
313 if ((ret2 = av_new_packet(pkt, ret)) < 0)
316 //read non-20-bit audio data into lxf->temp so we can deplanarize it
317 buf = ast && ast->codec->codec_id != CODEC_ID_PCM_LXF ? lxf->temp : pkt->data;
319 if ((ret2 = avio_read(pb, buf, ret)) != ret) {
321 return ret2 < 0 ? ret2 : AVERROR_EOF;
324 pkt->stream_index = stream;
327 if(ast->codec->codec_id != CODEC_ID_PCM_LXF)
328 deplanarize(lxf, ast, pkt->data, ret);
330 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
331 if (((format >> 22) & 0x3) < 2)
332 pkt->flags |= AV_PKT_FLAG_KEY;
334 pkt->dts = lxf->frame_number++;
340 AVInputFormat ff_lxf_demuxer = {
342 .long_name = NULL_IF_CONFIG_SMALL("VR native stream format (LXF)"),
343 .priv_data_size = sizeof(LXFDemuxContext),
344 .read_probe = lxf_probe,
345 .read_header = lxf_read_header,
346 .read_packet = lxf_read_packet,
347 .codec_tag = (const AVCodecTag* const []){lxf_tags, 0},