1 /*
2 * Digital Speech Standard (DSS) demuxer
3 * Copyright (c) 2014 Oleksij Rempel <linux@rempel-privat.de>
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 "libavutil/channel_layout.h"
23 #include "libavutil/intreadwrite.h"
24
25 #include "avformat.h"
26 #include "internal.h"
27
28 #define DSS_HEAD_OFFSET_AUTHOR 0xc
29 #define DSS_AUTHOR_SIZE 16
30
31 #define DSS_HEAD_OFFSET_START_TIME 0x26
32 #define DSS_HEAD_OFFSET_END_TIME 0x32
33 #define DSS_TIME_SIZE 12
34
35 #define DSS_HEAD_OFFSET_ACODEC 0x2a4
36 #define DSS_ACODEC_DSS_SP 0x0 /* SP mode */
37 #define DSS_ACODEC_G723_1 0x2 /* LP mode */
38
39 #define DSS_HEAD_OFFSET_COMMENT 0x31e
40 #define DSS_COMMENT_SIZE 64
41
42 #define DSS_BLOCK_SIZE 512
43 #define DSS_AUDIO_BLOCK_HEADER_SIZE 6
44 #define DSS_FRAME_SIZE 42
45
46 static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
47
48 typedef struct DSSDemuxContext {
49 unsigned int audio_codec;
50 int counter;
51 int swap;
52 int dss_sp_swap_byte;
53 int8_t dss_sp_buf[DSS_FRAME_SIZE + 1];
54
55 int packet_size;
56 int dss_header_size;
57 } DSSDemuxContext;
58
dss_probe(const AVProbeData * p)59 static int dss_probe(const AVProbeData *p)
60 {
61 if ( AV_RL32(p->buf) != MKTAG(0x2, 'd', 's', 's')
62 && AV_RL32(p->buf) != MKTAG(0x3, 'd', 's', 's'))
63 return 0;
64
65 return AVPROBE_SCORE_MAX;
66 }
67
dss_read_metadata_date(AVFormatContext * s,unsigned int offset,const char * key)68 static int dss_read_metadata_date(AVFormatContext *s, unsigned int offset,
69 const char *key)
70 {
71 AVIOContext *pb = s->pb;
72 char datetime[64], string[DSS_TIME_SIZE + 1] = { 0 };
73 int y, month, d, h, minute, sec;
74 int ret;
75
76 avio_seek(pb, offset, SEEK_SET);
77
78 ret = avio_read(s->pb, string, DSS_TIME_SIZE);
79 if (ret < DSS_TIME_SIZE)
80 return ret < 0 ? ret : AVERROR_EOF;
81
82 if (sscanf(string, "%2d%2d%2d%2d%2d%2d", &y, &month, &d, &h, &minute, &sec) != 6)
83 return AVERROR_INVALIDDATA;
84 /* We deal with a two-digit year here, so set the default date to 2000
85 * and hope it will never be used in the next century. */
86 snprintf(datetime, sizeof(datetime), "%.4d-%.2d-%.2dT%.2d:%.2d:%.2d",
87 y + 2000, month, d, h, minute, sec);
88 return av_dict_set(&s->metadata, key, datetime, 0);
89 }
90
dss_read_metadata_string(AVFormatContext * s,unsigned int offset,unsigned int size,const char * key)91 static int dss_read_metadata_string(AVFormatContext *s, unsigned int offset,
92 unsigned int size, const char *key)
93 {
94 AVIOContext *pb = s->pb;
95 char *value;
96 int ret;
97
98 avio_seek(pb, offset, SEEK_SET);
99
100 value = av_mallocz(size + 1);
101 if (!value)
102 return AVERROR(ENOMEM);
103
104 ret = avio_read(s->pb, value, size);
105 if (ret < size) {
106 av_free(value);
107 return ret < 0 ? ret : AVERROR_EOF;
108 }
109
110 return av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
111 }
112
dss_read_header(AVFormatContext * s)113 static int dss_read_header(AVFormatContext *s)
114 {
115 DSSDemuxContext *ctx = s->priv_data;
116 AVIOContext *pb = s->pb;
117 AVStream *st;
118 int ret, version;
119
120 st = avformat_new_stream(s, NULL);
121 if (!st)
122 return AVERROR(ENOMEM);
123
124 version = avio_r8(pb);
125 ctx->dss_header_size = version * DSS_BLOCK_SIZE;
126
127 ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_AUTHOR,
128 DSS_AUTHOR_SIZE, "author");
129 if (ret)
130 return ret;
131
132 ret = dss_read_metadata_date(s, DSS_HEAD_OFFSET_END_TIME, "date");
133 if (ret)
134 return ret;
135
136 ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_COMMENT,
137 DSS_COMMENT_SIZE, "comment");
138 if (ret)
139 return ret;
140
141 avio_seek(pb, DSS_HEAD_OFFSET_ACODEC, SEEK_SET);
142 ctx->audio_codec = avio_r8(pb);
143
144 if (ctx->audio_codec == DSS_ACODEC_DSS_SP) {
145 st->codecpar->codec_id = AV_CODEC_ID_DSS_SP;
146 st->codecpar->sample_rate = 11025;
147 } else if (ctx->audio_codec == DSS_ACODEC_G723_1) {
148 st->codecpar->codec_id = AV_CODEC_ID_G723_1;
149 st->codecpar->sample_rate = 8000;
150 } else {
151 avpriv_request_sample(s, "Support for codec %x in DSS",
152 ctx->audio_codec);
153 return AVERROR_PATCHWELCOME;
154 }
155
156 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
157 st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
158 st->codecpar->channels = 1;
159
160 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
161 st->start_time = 0;
162
163 /* Jump over header */
164
165 if (avio_seek(pb, ctx->dss_header_size, SEEK_SET) != ctx->dss_header_size)
166 return AVERROR(EIO);
167
168 ctx->counter = 0;
169 ctx->swap = 0;
170
171 return 0;
172 }
173
dss_skip_audio_header(AVFormatContext * s,AVPacket * pkt)174 static void dss_skip_audio_header(AVFormatContext *s, AVPacket *pkt)
175 {
176 DSSDemuxContext *ctx = s->priv_data;
177 AVIOContext *pb = s->pb;
178
179 avio_skip(pb, DSS_AUDIO_BLOCK_HEADER_SIZE);
180 ctx->counter += DSS_BLOCK_SIZE - DSS_AUDIO_BLOCK_HEADER_SIZE;
181 }
182
dss_sp_byte_swap(DSSDemuxContext * ctx,uint8_t * dst,const uint8_t * src)183 static void dss_sp_byte_swap(DSSDemuxContext *ctx,
184 uint8_t *dst, const uint8_t *src)
185 {
186 int i;
187
188 if (ctx->swap) {
189 for (i = 3; i < DSS_FRAME_SIZE; i += 2)
190 dst[i] = src[i];
191
192 for (i = 0; i < DSS_FRAME_SIZE - 2; i += 2)
193 dst[i] = src[i + 4];
194
195 dst[1] = ctx->dss_sp_swap_byte;
196 } else {
197 memcpy(dst, src, DSS_FRAME_SIZE);
198 ctx->dss_sp_swap_byte = src[DSS_FRAME_SIZE - 2];
199 }
200
201 /* make sure byte 40 is always 0 */
202 dst[DSS_FRAME_SIZE - 2] = 0;
203 ctx->swap ^= 1;
204 }
205
dss_sp_read_packet(AVFormatContext * s,AVPacket * pkt)206 static int dss_sp_read_packet(AVFormatContext *s, AVPacket *pkt)
207 {
208 DSSDemuxContext *ctx = s->priv_data;
209 AVStream *st = s->streams[0];
210 int read_size, ret, offset = 0, buff_offset = 0;
211 int64_t pos = avio_tell(s->pb);
212
213 if (ctx->counter == 0)
214 dss_skip_audio_header(s, pkt);
215
216 if (ctx->swap) {
217 read_size = DSS_FRAME_SIZE - 2;
218 buff_offset = 3;
219 } else
220 read_size = DSS_FRAME_SIZE;
221
222 ctx->packet_size = DSS_FRAME_SIZE - 1;
223
224 ret = av_new_packet(pkt, DSS_FRAME_SIZE);
225 if (ret < 0)
226 return ret;
227
228 pkt->duration = 264;
229 pkt->pos = pos;
230 pkt->stream_index = 0;
231 s->bit_rate = 8LL * ctx->packet_size * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
232
233 if (ctx->counter < read_size) {
234 ret = avio_read(s->pb, ctx->dss_sp_buf + buff_offset,
235 ctx->counter);
236 if (ret < ctx->counter)
237 goto error_eof;
238
239 offset = ctx->counter;
240 dss_skip_audio_header(s, pkt);
241 }
242 ctx->counter -= read_size;
243
244 ret = avio_read(s->pb, ctx->dss_sp_buf + offset + buff_offset,
245 read_size - offset);
246 if (ret < read_size - offset)
247 goto error_eof;
248
249 dss_sp_byte_swap(ctx, pkt->data, ctx->dss_sp_buf);
250
251 if (ctx->dss_sp_swap_byte < 0) {
252 return AVERROR(EAGAIN);
253 }
254
255 return pkt->size;
256
257 error_eof:
258 return ret < 0 ? ret : AVERROR_EOF;
259 }
260
dss_723_1_read_packet(AVFormatContext * s,AVPacket * pkt)261 static int dss_723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
262 {
263 DSSDemuxContext *ctx = s->priv_data;
264 AVStream *st = s->streams[0];
265 int size, byte, ret, offset;
266 int64_t pos = avio_tell(s->pb);
267
268 if (ctx->counter == 0)
269 dss_skip_audio_header(s, pkt);
270
271 /* We make one byte-step here. Don't forget to add offset. */
272 byte = avio_r8(s->pb);
273 if (byte == 0xff)
274 return AVERROR_INVALIDDATA;
275
276 size = frame_size[byte & 3];
277
278 ctx->packet_size = size;
279 ctx->counter--;
280
281 ret = av_new_packet(pkt, size);
282 if (ret < 0)
283 return ret;
284 pkt->pos = pos;
285
286 pkt->data[0] = byte;
287 offset = 1;
288 pkt->duration = 240;
289 s->bit_rate = 8LL * size-- * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
290
291 pkt->stream_index = 0;
292
293 if (ctx->counter < size) {
294 ret = avio_read(s->pb, pkt->data + offset,
295 ctx->counter);
296 if (ret < ctx->counter)
297 return ret < 0 ? ret : AVERROR_EOF;
298
299 offset += ctx->counter;
300 size -= ctx->counter;
301 ctx->counter = 0;
302 dss_skip_audio_header(s, pkt);
303 }
304 ctx->counter -= size;
305
306 ret = avio_read(s->pb, pkt->data + offset, size);
307 if (ret < size)
308 return ret < 0 ? ret : AVERROR_EOF;
309
310 return pkt->size;
311 }
312
dss_read_packet(AVFormatContext * s,AVPacket * pkt)313 static int dss_read_packet(AVFormatContext *s, AVPacket *pkt)
314 {
315 DSSDemuxContext *ctx = s->priv_data;
316
317 if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
318 return dss_sp_read_packet(s, pkt);
319 else
320 return dss_723_1_read_packet(s, pkt);
321 }
322
dss_read_seek(AVFormatContext * s,int stream_index,int64_t timestamp,int flags)323 static int dss_read_seek(AVFormatContext *s, int stream_index,
324 int64_t timestamp, int flags)
325 {
326 DSSDemuxContext *ctx = s->priv_data;
327 int64_t ret, seekto;
328 uint8_t header[DSS_AUDIO_BLOCK_HEADER_SIZE];
329 int offset;
330
331 if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
332 seekto = timestamp / 264 * 41 / 506 * 512;
333 else
334 seekto = timestamp / 240 * ctx->packet_size / 506 * 512;
335
336 if (seekto < 0)
337 seekto = 0;
338
339 seekto += ctx->dss_header_size;
340
341 ret = avio_seek(s->pb, seekto, SEEK_SET);
342 if (ret < 0)
343 return ret;
344
345 avio_read(s->pb, header, DSS_AUDIO_BLOCK_HEADER_SIZE);
346 ctx->swap = !!(header[0] & 0x80);
347 offset = 2*header[1] + 2*ctx->swap;
348 if (offset < DSS_AUDIO_BLOCK_HEADER_SIZE)
349 return AVERROR_INVALIDDATA;
350 if (offset == DSS_AUDIO_BLOCK_HEADER_SIZE) {
351 ctx->counter = 0;
352 offset = avio_skip(s->pb, -DSS_AUDIO_BLOCK_HEADER_SIZE);
353 } else {
354 ctx->counter = DSS_BLOCK_SIZE - offset;
355 offset = avio_skip(s->pb, offset - DSS_AUDIO_BLOCK_HEADER_SIZE);
356 }
357 ctx->dss_sp_swap_byte = -1;
358 return 0;
359 }
360
361
362 AVInputFormat ff_dss_demuxer = {
363 .name = "dss",
364 .long_name = NULL_IF_CONFIG_SMALL("Digital Speech Standard (DSS)"),
365 .priv_data_size = sizeof(DSSDemuxContext),
366 .read_probe = dss_probe,
367 .read_header = dss_read_header,
368 .read_packet = dss_read_packet,
369 .read_seek = dss_read_seek,
370 .extensions = "dss"
371 };
372