FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavformat/lxfdec.c
Date: 2026-04-24 19:58:39
Exec Total Coverage
Lines: 3 151 2.0%
Functions: 1 6 16.7%
Branches: 1 92 1.1%
Line Branch Exec Source
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 "demux.h"
28 #include "internal.h"
29
30 #define LXF_MAX_PACKET_HEADER_SIZE 256
31 #define LXF_HEADER_DATA_SIZE 120
32 #define LXF_IDENT "LEITCH\0"
33 #define LXF_IDENT_LENGTH 8
34 #define LXF_SAMPLERATE 48000
35
36 static const AVCodecTag lxf_tags[] = {
37 { AV_CODEC_ID_MJPEG, 0 },
38 { AV_CODEC_ID_MPEG1VIDEO, 1 },
39 { AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
40 { AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
41 { AV_CODEC_ID_DVVIDEO, 4 }, //DV25
42 { AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO
43 { AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
44 { AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
45 { AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
46 { AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
47 { AV_CODEC_ID_NONE, 0 },
48 };
49
50 typedef struct LXFDemuxContext {
51 int channels; ///< number of audio channels. zero means no audio
52 int frame_number; ///< current video frame
53 uint32_t video_format, packet_type, extended_size;
54 } LXFDemuxContext;
55
56 7480 static int lxf_probe(const AVProbeData *p)
57 {
58
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 7480 if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
59 ✗ return AVPROBE_SCORE_MAX;
60
61 7480 return 0;
62 }
63
64 /**
65 * Verify the checksum of an LXF packet header
66 *
67 * @param[in] header the packet header to check
68 * @return zero if the checksum is OK, non-zero otherwise
69 */
70 ✗ static int check_checksum(const uint8_t *header, int size)
71 {
72 int x;
73 ✗ uint32_t sum = 0;
74
75 ✗ for (x = 0; x < size; x += 4)
76 ✗ sum += AV_RL32(&header[x]);
77
78 ✗ return sum;
79 }
80
81 /**
82 * Read input until we find the next ident. If found, copy it to the header buffer
83 *
84 * @param[out] header where to copy the ident to
85 * @return 0 if an ident was found, < 0 on I/O error
86 */
87 ✗ static int lxf_sync(AVFormatContext *s, uint8_t *header)
88 {
89 uint8_t buf[LXF_IDENT_LENGTH];
90 int ret;
91
92 ✗ if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
93 ✗ return ret < 0 ? ret : AVERROR_EOF;
94
95 ✗ while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
96 ✗ if (avio_feof(s->pb))
97 ✗ return AVERROR_EOF;
98
99 ✗ memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
100 ✗ buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
101 }
102
103 ✗ memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
104
105 ✗ return 0;
106 }
107
108 /**
109 * Read and checksum the next packet header
110 *
111 * @return the size of the payload following the header or < 0 on failure
112 */
113 ✗ static int get_packet_header(AVFormatContext *s)
114 {
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;
119 AVStream *st;
120 uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
121 ✗ const uint8_t *p = header + LXF_IDENT_LENGTH;
122
123 //find and read the ident
124 ✗ if ((ret = lxf_sync(s, header)) < 0)
125 ✗ return ret;
126
127 ✗ ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
128 ✗ if (ret != 8)
129 ✗ return ret < 0 ? ret : AVERROR_EOF;
130
131 ✗ version = bytestream_get_le32(&p);
132 ✗ header_size = bytestream_get_le32(&p);
133 ✗ if (version > 1)
134 ✗ avpriv_request_sample(s, "Format version %"PRIu32, version);
135
136 ✗ if (header_size < (version ? 72 : 60) ||
137 ✗ header_size > LXF_MAX_PACKET_HEADER_SIZE ||
138 ✗ (header_size & 3)) {
139 ✗ av_log(s, AV_LOG_ERROR, "Invalid header size 0x%"PRIx32"\n", header_size);
140 ✗ return AVERROR_INVALIDDATA;
141 }
142
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;
148
149 ✗ if (check_checksum(header, header_size))
150 ✗ av_log(s, AV_LOG_ERROR, "checksum error\n");
151
152 ✗ lxf->packet_type = bytestream_get_le32(&p);
153 ✗ p += version ? 20 : 12;
154
155 ✗ lxf->extended_size = 0;
156 ✗ switch (lxf->packet_type) {
157 ✗ case 0:
158 //video
159 ✗ lxf->video_format = bytestream_get_le32(&p);
160 ✗ ret = bytestream_get_le32(&p);
161 //skip VBI data and metadata
162 ✗ avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
163 ✗ (int64_t)(uint32_t)AV_RL32(p + 12));
164 ✗ break;
165 ✗ case 1:
166 //audio
167 ✗ if (s->nb_streams < 2) {
168 ✗ av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
169 ✗ break;
170 }
171
172 ✗ if (version == 0)
173 ✗ p += 8;
174 ✗ audio_format = bytestream_get_le32(&p);
175 ✗ channels = bytestream_get_le32(&p);
176 ✗ track_size = bytestream_get_le32(&p);
177
178 ✗ st = s->streams[1];
179
180 //set codec based on specified audio bitdepth
181 //we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
182 ✗ st->codecpar->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
183
184 ✗ if (st->codecpar->bits_per_coded_sample != (audio_format & 0x3F)) {
185 ✗ avpriv_report_missing_feature(s, "Not tightly packed PCM");
186 ✗ return AVERROR_PATCHWELCOME;
187 }
188
189 ✗ switch (st->codecpar->bits_per_coded_sample) {
190 ✗ case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
191 ✗ case 20: st->codecpar->codec_id = AV_CODEC_ID_PCM_LXF; break;
192 ✗ case 24: st->codecpar->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
193 ✗ case 32: st->codecpar->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
194 ✗ default:
195 ✗ avpriv_report_missing_feature(s, "PCM not 16-, 20-, 24- or 32-bits");
196 ✗ return AVERROR_PATCHWELCOME;
197 }
198
199 ✗ samples = track_size * 8LL / 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)
208 ✗ av_log(s, AV_LOG_WARNING,
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 ✗ if (av_popcount(channels) * (uint64_t)track_size > INT_MAX)
215 ✗ return AVERROR_INVALIDDATA;
216 //TODO: warning if track mask != (1 << channels) - 1?
217 ✗ ret = av_popcount(channels) * track_size;
218
219 ✗ break;
220 ✗ default:
221 ✗ tmp = bytestream_get_le32(&p);
222 ✗ ret = bytestream_get_le32(&p);
223 ✗ if (tmp == 1)
224 ✗ lxf->extended_size = bytestream_get_le32(&p);
225 ✗ break;
226 }
227
228 ✗ return ret;
229 }
230
231 ✗ static int lxf_read_header(AVFormatContext *s)
232 {
233 ✗ LXFDemuxContext *lxf = s->priv_data;
234 ✗ AVIOContext *pb = s->pb;
235 uint8_t header_data[LXF_HEADER_DATA_SIZE];
236 int ret;
237 AVStream *st;
238 uint32_t video_params, disk_params;
239 uint16_t record_date, expiration_date;
240
241 ✗ if ((ret = get_packet_header(s)) < 0)
242 ✗ return ret;
243
244 ✗ if (ret != LXF_HEADER_DATA_SIZE) {
245 ✗ av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
246 LXF_HEADER_DATA_SIZE, ret);
247 ✗ return AVERROR_INVALIDDATA;
248 }
249
250 ✗ if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
251 ✗ return ret < 0 ? ret : AVERROR_EOF;
252
253 ✗ if (!(st = avformat_new_stream(s, NULL)))
254 ✗ return AVERROR(ENOMEM);
255
256 ✗ st->duration = AV_RL32(&header_data[32]);
257 ✗ video_params = AV_RL32(&header_data[40]);
258 ✗ record_date = AV_RL16(&header_data[56]);
259 ✗ expiration_date = AV_RL16(&header_data[58]);
260 ✗ disk_params = AV_RL32(&header_data[116]);
261
262 ✗ st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
263 ✗ st->codecpar->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
264 ✗ st->codecpar->codec_tag = video_params & 0xF;
265 ✗ st->codecpar->codec_id = ff_codec_get_id(lxf_tags, st->codecpar->codec_tag);
266 ✗ ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS;
267
268 ✗ av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
269 ✗ record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
270 (record_date >> 11) & 0x1F);
271
272 ✗ av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
273 ✗ expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
274 (expiration_date >> 11) & 0x1F);
275
276 ✗ if ((video_params >> 22) & 1)
277 ✗ av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
278
279 ✗ if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
280 ✗ if (!(st = avformat_new_stream(s, NULL)))
281 ✗ return AVERROR(ENOMEM);
282
283 ✗ st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
284 ✗ st->codecpar->sample_rate = LXF_SAMPLERATE;
285 ✗ st->codecpar->ch_layout.nb_channels = lxf->channels;
286
287 ✗ avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
288 }
289
290 ✗ avio_skip(s->pb, lxf->extended_size);
291
292 ✗ return 0;
293 }
294
295 ✗ static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
296 {
297 ✗ LXFDemuxContext *lxf = s->priv_data;
298 ✗ AVIOContext *pb = s->pb;
299 uint32_t stream;
300 int ret, ret2;
301
302 ✗ if ((ret = get_packet_header(s)) < 0)
303 ✗ return ret;
304
305 ✗ stream = lxf->packet_type;
306
307 ✗ if (stream > 1) {
308 ✗ av_log(s, AV_LOG_WARNING,
309 "got packet with illegal stream index %"PRIu32"\n", stream);
310 ✗ return FFERROR_REDO;
311 }
312
313 ✗ if (stream == 1 && s->nb_streams < 2) {
314 ✗ av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
315 ✗ return AVERROR_INVALIDDATA;
316 }
317
318 ✗ if ((ret2 = av_new_packet(pkt, ret)) < 0)
319 ✗ return ret2;
320
321 ✗ if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
322 ✗ return ret2 < 0 ? ret2 : AVERROR_EOF;
323 }
324
325 ✗ pkt->stream_index = stream;
326
327 ✗ if (!stream) {
328 //picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
329 ✗ if (((lxf->video_format >> 22) & 0x3) < 2)
330 ✗ pkt->flags |= AV_PKT_FLAG_KEY;
331
332 ✗ pkt->dts = lxf->frame_number++;
333 }
334
335 ✗ return ret;
336 }
337
338 const FFInputFormat ff_lxf_demuxer = {
339 .p.name = "lxf",
340 .p.long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
341 .p.codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
342 .priv_data_size = sizeof(LXFDemuxContext),
343 .read_probe = lxf_probe,
344 .read_header = lxf_read_header,
345 .read_packet = lxf_read_packet,
346 };
347