libavformat/dss.c

   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 #include "libavutil/mem.h"
  25
  26 #include "avformat.h"
  27 #include "demux.h"
  28 #include "internal.h"
  29
  30 #define DSS_HEAD_OFFSET_AUTHOR        0xc
  31 #define DSS_AUTHOR_SIZE               16
  32
  33 #define DSS_HEAD_OFFSET_START_TIME    0x26
  34 #define DSS_HEAD_OFFSET_END_TIME      0x32
  35 #define DSS_TIME_SIZE                 12
  36
  37 #define DSS_HEAD_OFFSET_ACODEC        0x2a4
  38 #define DSS_ACODEC_DSS_SP             0x0    /* SP mode */
  39 #define DSS_ACODEC_G723_1             0x2    /* LP mode */
  40
  41 #define DSS_HEAD_OFFSET_COMMENT       0x31e
  42 #define DSS_COMMENT_SIZE              64
  43
  44 #define DSS_BLOCK_SIZE                512
  45 #define DSS_AUDIO_BLOCK_HEADER_SIZE   6
  46 #define DSS_FRAME_SIZE                42
  47
  48 static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
  49
  50 typedef struct DSSDemuxContext {
  51     unsigned int audio_codec;
  52     int counter;
  53     int swap;
  54     int dss_sp_swap_byte;
  55
  56     int packet_size;
  57     int dss_header_size;
  58 } DSSDemuxContext;
  59
  60 static int dss_probe(const AVProbeData *p)
  61 {
  62     if (   AV_RL32(p->buf) != MKTAG(0x2, 'd', 's', 's')
  63         && AV_RL32(p->buf) != MKTAG(0x3, 'd', 's', 's'))
  64         return 0;
  65
  66     return AVPROBE_SCORE_MAX;
  67 }
  68
  69 static int dss_read_metadata_date(AVFormatContext *s, unsigned int offset,
  70                                   const char *key)
  71 {
  72     AVIOContext *pb = s->pb;
  73     char datetime[64], string[DSS_TIME_SIZE + 1] = { 0 };
  74     int y, month, d, h, minute, sec;
  75     int ret;
  76
  77     avio_seek(pb, offset, SEEK_SET);
  78
  79     ret = avio_read(s->pb, string, DSS_TIME_SIZE);
  80     if (ret < DSS_TIME_SIZE)
  81         return ret < 0 ? ret : AVERROR_EOF;
  82
  83     if (sscanf(string, "%2d%2d%2d%2d%2d%2d", &y, &month, &d, &h, &minute, &sec) != 6)
  84         return AVERROR_INVALIDDATA;
  85     /* We deal with a two-digit year here, so set the default date to 2000
  86      * and hope it will never be used in the next century. */
  87     snprintf(datetime, sizeof(datetime), "%.4d-%.2d-%.2dT%.2d:%.2d:%.2d",
  88              y + 2000, month, d, h, minute, sec);
  89     return av_dict_set(&s->metadata, key, datetime, 0);
  90 }
  91
  92 static int dss_read_metadata_string(AVFormatContext *s, unsigned int offset,
  93                                     unsigned int size, const char *key)
  94 {
  95     AVIOContext *pb = s->pb;
  96     char *value;
  97     int ret;
  98
  99     avio_seek(pb, offset, SEEK_SET);
 100
 101     value = av_mallocz(size + 1);
 102     if (!value)
 103         return AVERROR(ENOMEM);
 104
 105     ret = avio_read(s->pb, value, size);
 106     if (ret < size) {
 107         av_free(value);
 108         return ret < 0 ? ret : AVERROR_EOF;
 109     }
 110
 111     return av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
 112 }
 113
 114 static int dss_read_header(AVFormatContext *s)
 115 {
 116     DSSDemuxContext *ctx = s->priv_data;
 117     AVIOContext *pb = s->pb;
 118     AVStream *st;
 119     int64_t ret64;
 120     int ret, version;
 121
 122     st = avformat_new_stream(s, NULL);
 123     if (!st)
 124         return AVERROR(ENOMEM);
 125
 126     version = avio_r8(pb);
 127     ctx->dss_header_size = version * DSS_BLOCK_SIZE;
 128
 129     ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_AUTHOR,
 130                                    DSS_AUTHOR_SIZE, "author");
 131     if (ret)
 132         return ret;
 133
 134     ret = dss_read_metadata_date(s, DSS_HEAD_OFFSET_END_TIME, "date");
 135     if (ret)
 136         return ret;
 137
 138     ret = dss_read_metadata_string(s, DSS_HEAD_OFFSET_COMMENT,
 139                                    DSS_COMMENT_SIZE, "comment");
 140     if (ret)
 141         return ret;
 142
 143     avio_seek(pb, DSS_HEAD_OFFSET_ACODEC, SEEK_SET);
 144     ctx->audio_codec = avio_r8(pb);
 145
 146     if (ctx->audio_codec == DSS_ACODEC_DSS_SP) {
 147         st->codecpar->codec_id    = AV_CODEC_ID_DSS_SP;
 148         st->codecpar->sample_rate = 11025;
 149         s->bit_rate = 8 * (DSS_FRAME_SIZE - 1) * st->codecpar->sample_rate
 150                         * 512 / (506 * 264);
 151     } else if (ctx->audio_codec == DSS_ACODEC_G723_1) {
 152         st->codecpar->codec_id    = AV_CODEC_ID_G723_1;
 153         st->codecpar->sample_rate = 8000;
 154     } else {
 155         avpriv_request_sample(s, "Support for codec %x in DSS",
 156                               ctx->audio_codec);
 157         return AVERROR_PATCHWELCOME;
 158     }
 159
 160     st->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
 161     st->codecpar->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
 162
 163     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
 164     st->start_time = 0;
 165
 166     /* Jump over header */
 167
 168     if ((ret64 = avio_seek(pb, ctx->dss_header_size, SEEK_SET)) < 0)
 169         return (int)ret64;
 170
 171     ctx->counter = 0;
 172     ctx->swap    = 0;
 173
 174     return 0;
 175 }
 176
 177 static void dss_skip_audio_header(AVFormatContext *s, AVPacket *pkt)
 178 {
 179     DSSDemuxContext *ctx = s->priv_data;
 180     AVIOContext *pb = s->pb;
 181
 182     avio_skip(pb, DSS_AUDIO_BLOCK_HEADER_SIZE);
 183     ctx->counter += DSS_BLOCK_SIZE - DSS_AUDIO_BLOCK_HEADER_SIZE;
 184 }
 185
 186 static void dss_sp_byte_swap(DSSDemuxContext *ctx, uint8_t *data)
 187 {
 188     int i;
 189
 190     if (ctx->swap) {
 191         for (i = 0; i < DSS_FRAME_SIZE - 2; i += 2)
 192             data[i] = data[i + 4];
 193
 194         /* Zero the padding. */
 195         data[DSS_FRAME_SIZE] = 0;
 196         data[1] = ctx->dss_sp_swap_byte;
 197     } else {
 198         ctx->dss_sp_swap_byte = data[DSS_FRAME_SIZE - 2];
 199     }
 200
 201     /* make sure byte 40 is always 0 */
 202     data[DSS_FRAME_SIZE - 2] = 0;
 203     ctx->swap             ^= 1;
 204 }
 205
 206 static int dss_sp_read_packet(AVFormatContext *s, AVPacket *pkt)
 207 {
 208     DSSDemuxContext *ctx = s->priv_data;
 209     int read_size, ret, offset = 0, buff_offset = 0;
 210     int64_t pos = avio_tell(s->pb);
 211
 212     if (ctx->counter == 0)
 213         dss_skip_audio_header(s, pkt);
 214
 215     if (ctx->swap) {
 216         read_size   = DSS_FRAME_SIZE - 2;
 217         buff_offset = 3;
 218     } else
 219         read_size = DSS_FRAME_SIZE;
 220
 221     ret = av_new_packet(pkt, DSS_FRAME_SIZE);
 222     if (ret < 0)
 223         return ret;
 224
 225     pkt->duration     = 264;
 226     pkt->pos = pos;
 227     pkt->stream_index = 0;
 228
 229     if (ctx->counter < read_size) {
 230         ret = avio_read(s->pb, pkt->data + buff_offset,
 231                         ctx->counter);
 232         if (ret < ctx->counter)
 233             goto error_eof;
 234
 235         offset = ctx->counter;
 236         dss_skip_audio_header(s, pkt);
 237     }
 238     ctx->counter -= read_size;
 239
 240     /* This will write one byte into pkt's padding if buff_offset == 3 */
 241     ret = avio_read(s->pb, pkt->data + offset + buff_offset,
 242                     read_size - offset);
 243     if (ret < read_size - offset)
 244         goto error_eof;
 245
 246     dss_sp_byte_swap(ctx, pkt->data);
 247
 248     if (ctx->dss_sp_swap_byte < 0) {
 249         return AVERROR(EAGAIN);
 250     }
 251
 252     return 0;
 253
 254 error_eof:
 255     return ret < 0 ? ret : AVERROR_EOF;
 256 }
 257
 258 static int dss_723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
 259 {
 260     DSSDemuxContext *ctx = s->priv_data;
 261     AVStream *st = s->streams[0];
 262     int size, byte, ret, offset;
 263     int64_t pos = avio_tell(s->pb);
 264
 265     if (ctx->counter == 0)
 266         dss_skip_audio_header(s, pkt);
 267
 268     /* We make one byte-step here. Don't forget to add offset. */
 269     byte = avio_r8(s->pb);
 270     if (byte == 0xff)
 271         return AVERROR_INVALIDDATA;
 272
 273     size = frame_size[byte & 3];
 274
 275     ctx->packet_size = size;
 276     ctx->counter--;
 277
 278     ret = av_new_packet(pkt, size);
 279     if (ret < 0)
 280         return ret;
 281     pkt->pos = pos;
 282
 283     pkt->data[0]  = byte;
 284     offset        = 1;
 285     pkt->duration = 240;
 286     s->bit_rate = 8LL * size-- * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
 287
 288     pkt->stream_index = 0;
 289
 290     if (ctx->counter < size) {
 291         ret = avio_read(s->pb, pkt->data + offset,
 292                         ctx->counter);
 293         if (ret < ctx->counter)
 294             return ret < 0 ? ret : AVERROR_EOF;
 295
 296         offset += ctx->counter;
 297         size   -= ctx->counter;
 298         ctx->counter = 0;
 299         dss_skip_audio_header(s, pkt);
 300     }
 301     ctx->counter -= size;
 302
 303     ret = avio_read(s->pb, pkt->data + offset, size);
 304     if (ret < size)
 305         return ret < 0 ? ret : AVERROR_EOF;
 306
 307     return 0;
 308 }
 309
 310 static int dss_read_packet(AVFormatContext *s, AVPacket *pkt)
 311 {
 312     DSSDemuxContext *ctx = s->priv_data;
 313
 314     if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
 315         return dss_sp_read_packet(s, pkt);
 316     else
 317         return dss_723_1_read_packet(s, pkt);
 318 }
 319
 320 static int dss_read_seek(AVFormatContext *s, int stream_index,
 321                          int64_t timestamp, int flags)
 322 {
 323     DSSDemuxContext *ctx = s->priv_data;
 324     int64_t ret, seekto;
 325     uint8_t header[DSS_AUDIO_BLOCK_HEADER_SIZE];
 326     int offset;
 327
 328     if (ctx->audio_codec == DSS_ACODEC_DSS_SP)
 329         seekto = timestamp / 264 * 41 / 506 * 512;
 330     else
 331         seekto = timestamp / 240 * ctx->packet_size / 506 * 512;
 332
 333     if (seekto < 0)
 334         seekto = 0;
 335
 336     seekto += ctx->dss_header_size;
 337
 338     ret = avio_seek(s->pb, seekto, SEEK_SET);
 339     if (ret < 0)
 340         return ret;
 341
 342     avio_read(s->pb, header, DSS_AUDIO_BLOCK_HEADER_SIZE);
 343     ctx->swap = !!(header[0] & 0x80);
 344     offset = 2*header[1] + 2*ctx->swap;
 345     if (offset < DSS_AUDIO_BLOCK_HEADER_SIZE)
 346         return AVERROR_INVALIDDATA;
 347     if (offset == DSS_AUDIO_BLOCK_HEADER_SIZE) {
 348         ctx->counter = 0;
 349         offset = avio_skip(s->pb, -DSS_AUDIO_BLOCK_HEADER_SIZE);
 350     } else {
 351         ctx->counter = DSS_BLOCK_SIZE - offset;
 352         offset = avio_skip(s->pb, offset - DSS_AUDIO_BLOCK_HEADER_SIZE);
 353     }
 354     ctx->dss_sp_swap_byte = -1;
 355     return 0;
 356 }
 357
 358
 359 const FFInputFormat ff_dss_demuxer = {
 360     .p.name         = "dss",
 361     .p.long_name    = NULL_IF_CONFIG_SMALL("Digital Speech Standard (DSS)"),
 362     .p.extensions   = "dss",
 363     .priv_data_size = sizeof(DSSDemuxContext),
 364     .read_probe     = dss_probe,
 365     .read_header    = dss_read_header,
 366     .read_packet    = dss_read_packet,
 367     .read_seek      = dss_read_seek,
 368 };