2 * Digital Speech Standard (DSS) demuxer
3 * Copyright (c) 2014 Oleksij Rempel <linux@rempel-privat.de>
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/channel_layout.h"
23 #include "libavutil/intreadwrite.h"
28 #define DSS_HEAD_OFFSET_AUTHOR 0xc
29 #define DSS_AUTHOR_SIZE 16
31 #define DSS_HEAD_OFFSET_START_TIME 0x26
32 #define DSS_HEAD_OFFSET_END_TIME 0x32
33 #define DSS_TIME_SIZE 12
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 */
39 #define DSS_HEAD_OFFSET_COMMENT 0x31e
40 #define DSS_COMMENT_SIZE 64
42 #define DSS_BLOCK_SIZE 512
43 #define DSS_AUDIO_BLOCK_HEADER_SIZE 6
44 #define DSS_FRAME_SIZE 42
46 static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
48 typedef struct DSSDemuxContext {
49 unsigned int audio_codec;
58 static int dss_probe(const AVProbeData *p)
60 if ( AV_RL32(p->buf) != MKTAG(0x2, 'd', 's', 's')
61 && AV_RL32(p->buf) != MKTAG(0x3, 'd', 's', 's'))
64 return AVPROBE_SCORE_MAX;
67 static int dss_read_metadata_date(AVFormatContext *s, unsigned int offset,
70 AVIOContext *pb = s->pb;
71 char datetime[64], string[DSS_TIME_SIZE + 1] = { 0 };
72 int y, month, d, h, minute, sec;
75 avio_seek(pb, offset, SEEK_SET);
77 ret = avio_read(s->pb, string, DSS_TIME_SIZE);
78 if (ret < DSS_TIME_SIZE)
79 return ret < 0 ? ret : AVERROR_EOF;
81 if (sscanf(string, "%2d%2d%2d%2d%2d%2d", &y, &month, &d, &h, &minute, &sec) != 6)
82 return AVERROR_INVALIDDATA;
83 /* We deal with a two-digit year here, so set the default date to 2000
84 * and hope it will never be used in the next century. */
85 snprintf(datetime, sizeof(datetime), "%.4d-%.2d-%.2dT%.2d:%.2d:%.2d",
86 y + 2000, month, d, h, minute, sec);
87 return av_dict_set(&s->metadata, key, datetime, 0);
90 static int dss_read_metadata_string(AVFormatContext *s, unsigned int offset,
91 unsigned int size, const char *key)
93 AVIOContext *pb = s->pb;
97 avio_seek(pb, offset, SEEK_SET);
99 value = av_mallocz(size + 1);
101 return AVERROR(ENOMEM);
103 ret = avio_read(s->pb, value, size);
106 return ret < 0 ? ret : AVERROR_EOF;
109 return av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
112 static int dss_read_header(AVFormatContext *s)
114 DSSDemuxContext *ctx = s->priv_data;
115 AVIOContext *pb = s->pb;
119 st = avformat_new_stream(s, NULL);
121 return AVERROR(ENOMEM);
123 version = avio_r8(pb);
124 ctx->dss_header_size = version * DSS_BLOCK_SIZE;
126 ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_AUTHOR,
127 DSS_AUTHOR_SIZE, "author");
131 ret = dss_read_metadata_date(s, DSS_HEAD_OFFSET_END_TIME, "date");
135 ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_COMMENT,
136 DSS_COMMENT_SIZE, "comment");
140 avio_seek(pb, DSS_HEAD_OFFSET_ACODEC, SEEK_SET);
141 ctx->audio_codec = avio_r8(pb);
143 if (ctx->audio_codec == DSS_ACODEC_DSS_SP) {
144 st->codecpar->codec_id = AV_CODEC_ID_DSS_SP;
145 st->codecpar->sample_rate = 11025;
146 s->bit_rate = 8 * (DSS_FRAME_SIZE - 1) * st->codecpar->sample_rate
148 } else if (ctx->audio_codec == DSS_ACODEC_G723_1) {
149 st->codecpar->codec_id = AV_CODEC_ID_G723_1;
150 st->codecpar->sample_rate = 8000;
152 avpriv_request_sample(s, "Support for codec %x in DSS",
154 return AVERROR_PATCHWELCOME;
157 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
158 st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
159 st->codecpar->channels = 1;
161 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
164 /* Jump over header */
166 if (avio_seek(pb, ctx->dss_header_size, SEEK_SET) != ctx->dss_header_size)
175 static void dss_skip_audio_header(AVFormatContext *s, AVPacket *pkt)
177 DSSDemuxContext *ctx = s->priv_data;
178 AVIOContext *pb = s->pb;
180 avio_skip(pb, DSS_AUDIO_BLOCK_HEADER_SIZE);
181 ctx->counter += DSS_BLOCK_SIZE - DSS_AUDIO_BLOCK_HEADER_SIZE;
184 static void dss_sp_byte_swap(DSSDemuxContext *ctx, uint8_t *data)
189 for (i = 0; i < DSS_FRAME_SIZE - 2; i += 2)
190 data[i] = data[i + 4];
192 /* Zero the padding. */
193 data[DSS_FRAME_SIZE] = 0;
194 data[1] = ctx->dss_sp_swap_byte;
196 ctx->dss_sp_swap_byte = data[DSS_FRAME_SIZE - 2];
199 /* make sure byte 40 is always 0 */
200 data[DSS_FRAME_SIZE - 2] = 0;
204 static int dss_sp_read_packet(AVFormatContext *s, AVPacket *pkt)
206 DSSDemuxContext *ctx = s->priv_data;
207 int read_size, ret, offset = 0, buff_offset = 0;
208 int64_t pos = avio_tell(s->pb);
210 if (ctx->counter == 0)
211 dss_skip_audio_header(s, pkt);
214 read_size = DSS_FRAME_SIZE - 2;
217 read_size = DSS_FRAME_SIZE;
219 ret = av_new_packet(pkt, DSS_FRAME_SIZE);
225 pkt->stream_index = 0;
227 if (ctx->counter < read_size) {
228 ret = avio_read(s->pb, pkt->data + buff_offset,
230 if (ret < ctx->counter)
233 offset = ctx->counter;
234 dss_skip_audio_header(s, pkt);
236 ctx->counter -= read_size;
238 /* This will write one byte into pkt's padding if buff_offset == 3 */
239 ret = avio_read(s->pb, pkt->data + offset + buff_offset,
241 if (ret < read_size - offset)
244 dss_sp_byte_swap(ctx, pkt->data);
246 if (ctx->dss_sp_swap_byte < 0) {
247 return AVERROR(EAGAIN);
253 return ret < 0 ? ret : AVERROR_EOF;
256 static int dss_723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
258 DSSDemuxContext *ctx = s->priv_data;
259 AVStream *st = s->streams[0];
260 int size, byte, ret, offset;
261 int64_t pos = avio_tell(s->pb);
263 if (ctx->counter == 0)
264 dss_skip_audio_header(s, pkt);
266 /* We make one byte-step here. Don't forget to add offset. */
267 byte = avio_r8(s->pb);
269 return AVERROR_INVALIDDATA;
271 size = frame_size[byte & 3];
273 ctx->packet_size = size;
276 ret = av_new_packet(pkt, size);
284 s->bit_rate = 8LL * size-- * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
286 pkt->stream_index = 0;
288 if (ctx->counter < size) {
289 ret = avio_read(s->pb, pkt->data + offset,
291 if (ret < ctx->counter)
292 return ret < 0 ? ret : AVERROR_EOF;
294 offset += ctx->counter;
295 size -= ctx->counter;
297 dss_skip_audio_header(s, pkt);
299 ctx->counter -= size;
301 ret = avio_read(s->pb, pkt->data + offset, size);
303 return ret < 0 ? ret : AVERROR_EOF;
308 static int dss_read_packet(AVFormatContext *s, AVPacket *pkt)
310 DSSDemuxContext *ctx = s->priv_data;
312 if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
313 return dss_sp_read_packet(s, pkt);
315 return dss_723_1_read_packet(s, pkt);
318 static int dss_read_seek(AVFormatContext *s, int stream_index,
319 int64_t timestamp, int flags)
321 DSSDemuxContext *ctx = s->priv_data;
323 uint8_t header[DSS_AUDIO_BLOCK_HEADER_SIZE];
326 if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
327 seekto = timestamp / 264 * 41 / 506 * 512;
329 seekto = timestamp / 240 * ctx->packet_size / 506 * 512;
334 seekto += ctx->dss_header_size;
336 ret = avio_seek(s->pb, seekto, SEEK_SET);
340 avio_read(s->pb, header, DSS_AUDIO_BLOCK_HEADER_SIZE);
341 ctx->swap = !!(header[0] & 0x80);
342 offset = 2*header[1] + 2*ctx->swap;
343 if (offset < DSS_AUDIO_BLOCK_HEADER_SIZE)
344 return AVERROR_INVALIDDATA;
345 if (offset == DSS_AUDIO_BLOCK_HEADER_SIZE) {
347 offset = avio_skip(s->pb, -DSS_AUDIO_BLOCK_HEADER_SIZE);
349 ctx->counter = DSS_BLOCK_SIZE - offset;
350 offset = avio_skip(s->pb, offset - DSS_AUDIO_BLOCK_HEADER_SIZE);
352 ctx->dss_sp_swap_byte = -1;
357 AVInputFormat ff_dss_demuxer = {
359 .long_name = NULL_IF_CONFIG_SMALL("Digital Speech Standard (DSS)"),
360 .priv_data_size = sizeof(DSSDemuxContext),
361 .read_probe = dss_probe,
362 .read_header = dss_read_header,
363 .read_packet = dss_read_packet,
364 .read_seek = dss_read_seek,