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"
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 #define LXF_MAX_AUDIO_PACKET (8008*15*4) ///< 15-channel 32-bit NTSC audio frame
34 static const AVCodecTag lxf_tags[] = {
35 { AV_CODEC_ID_MJPEG, 0 },
36 { AV_CODEC_ID_MPEG1VIDEO, 1 },
37 { AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
38 { AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
39 { AV_CODEC_ID_DVVIDEO, 4 }, //DV25
40 { AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO
41 { AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
42 { AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
43 { AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
44 { AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
45 { AV_CODEC_ID_NONE, 0 },
49 int channels; ///< number of audio channels. zero means no audio
50 int frame_number; ///< current video frame
51 uint32_t video_format, packet_type, extended_size;
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, int size)
73 for (x = 0; x < 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)) {
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 * @return the size of the payload following the header or < 0 on failure
111 static int get_packet_header(AVFormatContext *s)
113 LXFDemuxContext *lxf = s->priv_data;
114 AVIOContext *pb = s->pb;
115 int track_size, samples, ret;
116 uint32_t version, audio_format, header_size, channels, tmp;
118 uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
121 //find and read the ident
122 if ((ret = sync(s, header)) < 0)
125 ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
127 return ret < 0 ? ret : AVERROR_EOF;
129 p = header + LXF_IDENT_LENGTH;
130 version = bytestream_get_le32(&p);
131 header_size = bytestream_get_le32(&p);
133 av_log_ask_for_sample(s, "Unknown format version %i\n", version);
134 if (header_size < (version ? 72 : 60) ||
135 header_size > LXF_MAX_PACKET_HEADER_SIZE ||
137 av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
138 return AVERROR_INVALIDDATA;
141 //read the rest of the packet header
142 if ((ret = avio_read(pb, header + (p - header),
143 header_size - (p - header))) !=
144 header_size - (p - header)) {
145 return ret < 0 ? ret : AVERROR_EOF;
148 if (check_checksum(header, header_size))
149 av_log(s, AV_LOG_ERROR, "checksum error\n");
151 lxf->packet_type = bytestream_get_le32(&p);
152 p += version ? 20 : 12;
154 lxf->extended_size = 0;
155 switch (lxf->packet_type) {
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));
166 if (!s->streams || !(st = s->streams[1])) {
167 av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
171 if (version == 0) p += 8;
172 audio_format = bytestream_get_le32(&p);
173 channels = bytestream_get_le32(&p);
174 track_size = bytestream_get_le32(&p);
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;
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;
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;
191 av_log(s, AV_LOG_WARNING,
192 "only 16-, 20-, 24- and 32-bit PCM currently supported\n");
193 return AVERROR_PATCHWELCOME;
196 samples = track_size * 8 / st->codec->bits_per_coded_sample;
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);
203 //assume PAL, but warn if we don't have 1920 samples
204 if (samples != LXF_SAMPLERATE / 25)
205 av_log(s, AV_LOG_WARNING,
206 "video doesn't seem to be PAL or NTSC. guessing PAL\n");
208 avpriv_set_pts_info(s->streams[0], 64, 1, 25);
211 //TODO: warning if track mask != (1 << channels) - 1?
212 ret = av_popcount(channels) * track_size;
216 tmp = bytestream_get_le32(&p);
217 ret = bytestream_get_le32(&p);
219 lxf->extended_size = bytestream_get_le32(&p);
226 static int lxf_read_header(AVFormatContext *s)
228 LXFDemuxContext *lxf = s->priv_data;
229 AVIOContext *pb = s->pb;
230 uint8_t header_data[LXF_HEADER_DATA_SIZE];
233 uint32_t video_params, disk_params;
234 uint16_t record_date, expiration_date;
236 if ((ret = get_packet_header(s)) < 0)
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;
245 if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
246 return ret < 0 ? ret : AVERROR_EOF;
248 if (!(st = avformat_new_stream(s, NULL)))
249 return AVERROR(ENOMEM);
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]);
257 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
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);
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);
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);
270 if ((video_params >> 22) & 1)
271 av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
273 if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
274 if (!(st = avformat_new_stream(s, NULL)))
275 return AVERROR(ENOMEM);
277 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
278 st->codec->sample_rate = LXF_SAMPLERATE;
279 st->codec->channels = lxf->channels;
281 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
284 avio_skip(s->pb, lxf->extended_size);
289 static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
291 LXFDemuxContext *lxf = s->priv_data;
292 AVIOContext *pb = s->pb;
293 AVStream *ast = NULL;
297 if ((ret = get_packet_header(s)) < 0)
300 stream = lxf->packet_type;
303 av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
304 return AVERROR(EAGAIN);
307 if (stream == 1 && !(ast = s->streams[1])) {
308 av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
309 return AVERROR_INVALIDDATA;
312 //make sure the data fits in the de-planerization buffer
313 if (ast && ret > LXF_MAX_AUDIO_PACKET) {
314 av_log(s, AV_LOG_ERROR, "audio packet too large (%i > %i)\n",
315 ret, LXF_MAX_AUDIO_PACKET);
316 return AVERROR_INVALIDDATA;
319 if ((ret2 = av_new_packet(pkt, ret)) < 0)
322 if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
324 return ret2 < 0 ? ret2 : AVERROR_EOF;
327 pkt->stream_index = stream;
330 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
331 if (((lxf->video_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 (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},