libavformat/moflex.c

   1 /*
   2  * MOFLEX demuxer
   3  * Copyright (c) 2015-2016 Florian Nouwt
   4  * Copyright (c) 2017 Adib Surani
   5  * Copyright (c) 2020 Paul B Mahol
   6  *
   7  * This file is part of FFmpeg.
   8  *
   9  * FFmpeg is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * FFmpeg is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with FFmpeg; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include "libavcodec/bytestream.h"
  25
  26 #include "avformat.h"
  27 #include "demux.h"
  28 #include "internal.h"
  29
  30 typedef struct BitReader {
  31     unsigned last;
  32     unsigned pos;
  33 } BitReader;
  34
  35 typedef struct MOFLEXDemuxContext {
  36     unsigned size;
  37     int64_t pos;
  38     int64_t ts;
  39     int flags;
  40     int in_block;
  41
  42     BitReader br;
  43 } MOFLEXDemuxContext;
  44
  45 static int pop(BitReader *br, AVIOContext *pb)
  46 {
  47     if (avio_feof(pb))
  48         return AVERROR_EOF;
  49
  50     if ((br->pos & 7) == 0)
  51         br->last = (unsigned)avio_r8(pb) << 24U;
  52     else
  53         br->last <<= 1;
  54
  55     br->pos++;
  56     return !!(br->last & 0x80000000);
  57 }
  58
  59 static int pop_int(BitReader *br, AVIOContext *pb, int n)
  60 {
  61     int value = 0;
  62
  63     for (int i = 0; i < n; i++) {
  64         int ret = pop(br, pb);
  65
  66         if (ret < 0)
  67             return ret;
  68         if (ret > INT_MAX - value - value)
  69             return AVERROR_INVALIDDATA;
  70         value = 2 * value + ret;
  71     }
  72
  73     return value;
  74 }
  75
  76 static int pop_length(BitReader *br, AVIOContext *pb)
  77 {
  78     int ret, n = 1;
  79
  80     while ((ret = pop(br, pb)) == 0)
  81         n++;
  82
  83     if (ret < 0)
  84         return ret;
  85     return n;
  86 }
  87
  88 static int read_var_byte(AVFormatContext *s, unsigned *out)
  89 {
  90     AVIOContext *pb = s->pb;
  91     unsigned value = 0, data;
  92
  93     data = avio_r8(pb);
  94     if (!(data & 0x80)) {
  95         *out = data;
  96         return 0;
  97     }
  98
  99     value = (data & 0x7F) << 7;
 100     data = avio_r8(pb);
 101     if (!(data & 0x80)) {
 102         value |= data;
 103         *out = value;
 104         return 0;
 105     }
 106
 107     value = ((data & 0x7F) | value) << 7;
 108     data = avio_r8(pb);
 109     if (!(data & 0x80)) {
 110         value |= data;
 111         *out = value;
 112         return 0;
 113     }
 114
 115     value = (((data & 0x7F) | value) << 7) | avio_r8(pb);
 116     *out = value;
 117
 118     return 0;
 119 }
 120
 121 static int moflex_probe(const AVProbeData *p)
 122 {
 123     GetByteContext gb;
 124     int score = 0;
 125
 126     bytestream2_init(&gb, p->buf, p->buf_size);
 127
 128     if (bytestream2_get_be16(&gb) != 0x4C32)
 129         return 0;
 130     score += 10;
 131
 132     bytestream2_skip(&gb, 10);
 133     if (bytestream2_get_be16(&gb) == 0)
 134         return 0;
 135     score += 5;
 136
 137     while (bytestream2_get_bytes_left(&gb) > 0) {
 138         int type = bytestream2_get_byte(&gb);
 139         int size = bytestream2_get_byte(&gb);
 140
 141         if (type == 0) {
 142             score += 5 * (size == 0);
 143             break;
 144         }
 145         if ((type == 1 && size == 12) ||
 146             (type == 2 && size ==  6) ||
 147             (type == 3 && size == 13) ||
 148             (type == 4 && size ==  2))
 149             score += 20;
 150         bytestream2_skip(&gb, size);
 151     }
 152
 153     return FFMIN(AVPROBE_SCORE_MAX, score);
 154 }
 155
 156 static int moflex_read_sync(AVFormatContext *s)
 157 {
 158     MOFLEXDemuxContext *m = s->priv_data;
 159     AVIOContext *pb = s->pb;
 160
 161     if (avio_rb16(pb) != 0x4C32) {
 162         if (avio_feof(pb))
 163             return AVERROR_EOF;
 164         avio_seek(pb, -2, SEEK_CUR);
 165         return 1;
 166     }
 167
 168     avio_skip(pb, 2);
 169     m->ts = avio_rb64(pb);
 170     m->size = avio_rb16(pb) + 1;
 171
 172     while (!avio_feof(pb)) {
 173         unsigned type, ssize, codec_id = 0;
 174         unsigned codec_type, width = 0, height = 0, sample_rate = 0, channels = 0;
 175         int stream_index = -1;
 176         AVRational tb = av_make_q(0, 1);
 177
 178         read_var_byte(s, &type);
 179         read_var_byte(s, &ssize);
 180
 181         switch (type) {
 182         case 0:
 183             if (ssize > 0)
 184                 avio_skip(pb, ssize);
 185             return 0;
 186         case 2:
 187             codec_type = AVMEDIA_TYPE_AUDIO;
 188             stream_index = avio_r8(pb);
 189             codec_id = avio_r8(pb);
 190             switch (codec_id) {
 191             case 0: codec_id = AV_CODEC_ID_FASTAUDIO; break;
 192             case 1: codec_id = AV_CODEC_ID_ADPCM_IMA_MOFLEX; break;
 193             case 2: codec_id = AV_CODEC_ID_PCM_S16LE; break;
 194             default:
 195                 av_log(s, AV_LOG_ERROR, "Unsupported audio codec: %d\n", codec_id);
 196                 return AVERROR_PATCHWELCOME;
 197             }
 198             sample_rate = avio_rb24(pb) + 1;
 199             tb = av_make_q(1, sample_rate);
 200             channels = avio_r8(pb) + 1;
 201             break;
 202         case 1:
 203         case 3:
 204             codec_type = AVMEDIA_TYPE_VIDEO;
 205             stream_index = avio_r8(pb);
 206             codec_id = avio_r8(pb);
 207             switch (codec_id) {
 208             case 0: codec_id = AV_CODEC_ID_MOBICLIP; break;
 209             default:
 210                 av_log(s, AV_LOG_ERROR, "Unsupported video codec: %d\n", codec_id);
 211                 return AVERROR_PATCHWELCOME;
 212             }
 213             tb.den = avio_rb16(pb);
 214             tb.num = avio_rb16(pb);
 215             width = avio_rb16(pb);
 216             height = avio_rb16(pb);
 217             avio_skip(pb, type == 3 ? 3 : 2);
 218             break;
 219         case 4:
 220             codec_type = AVMEDIA_TYPE_DATA;
 221             stream_index = avio_r8(pb);
 222             avio_skip(pb, 1);
 223             break;
 224         }
 225
 226         if (stream_index == s->nb_streams) {
 227             AVStream *st = avformat_new_stream(s, NULL);
 228
 229             if (!st)
 230                 return AVERROR(ENOMEM);
 231
 232             st->codecpar->codec_type = codec_type;
 233             st->codecpar->codec_id   = codec_id;
 234             st->codecpar->width      = width;
 235             st->codecpar->height     = height;
 236             st->codecpar->sample_rate= sample_rate;
 237             st->codecpar->ch_layout.nb_channels = channels;
 238             st->priv_data            = av_packet_alloc();
 239             if (!st->priv_data)
 240                 return AVERROR(ENOMEM);
 241
 242             if (tb.num)
 243                 avpriv_set_pts_info(st, 63, tb.num, tb.den);
 244         }
 245     }
 246
 247     return 0;
 248 }
 249
 250 static int moflex_read_header(AVFormatContext *s)
 251 {
 252     int ret;
 253
 254     ret = moflex_read_sync(s);
 255     if (ret < 0)
 256         return ret;
 257
 258     s->ctx_flags |= AVFMTCTX_NOHEADER;
 259     avio_seek(s->pb, 0, SEEK_SET);
 260
 261     return 0;
 262 }
 263
 264 static int moflex_read_packet(AVFormatContext *s, AVPacket *pkt)
 265 {
 266     MOFLEXDemuxContext *m = s->priv_data;
 267     AVIOContext *pb = s->pb;
 268     BitReader *br = &m->br;
 269     int ret;
 270
 271     while (!avio_feof(pb)) {
 272         if (!m->in_block) {
 273             m->pos = avio_tell(pb);
 274
 275             ret = moflex_read_sync(s);
 276             if (ret < 0)
 277                 return ret;
 278
 279             m->flags = avio_r8(pb);
 280             if (m->flags & 2)
 281                 avio_skip(pb, 2);
 282         }
 283
 284         while ((avio_tell(pb) < m->pos + m->size) && !avio_feof(pb) && avio_r8(pb)) {
 285             int stream_index, bits, pkt_size, endframe;
 286             AVPacket *packet;
 287
 288             m->in_block = 1;
 289
 290             avio_seek(pb, -1, SEEK_CUR);
 291             br->pos = br->last = 0;
 292
 293             bits = pop_length(br, pb);
 294             if (bits < 0)
 295                 return bits;
 296             stream_index = pop_int(br, pb, bits);
 297             if (stream_index < 0)
 298                 return stream_index;
 299             if (stream_index >= s->nb_streams)
 300                 return AVERROR_INVALIDDATA;
 301
 302             endframe = pop(br, pb);
 303             if (endframe < 0)
 304                 return endframe;
 305             if (endframe) {
 306                 bits = pop_length(br, pb);
 307                 if (bits < 0)
 308                     return bits;
 309                 pop_int(br, pb, bits);
 310                 pop(br, pb);
 311                 bits = pop_length(br, pb);
 312                 if (bits < 0)
 313                     return bits;
 314                 pop_int(br, pb, bits * 2 + 26);
 315             }
 316
 317             pkt_size = pop_int(br, pb, 13) + 1;
 318             if (pkt_size > m->size)
 319                 return AVERROR_INVALIDDATA;
 320             packet   = s->streams[stream_index]->priv_data;
 321             if (!packet) {
 322                 avio_skip(pb, pkt_size);
 323                 continue;
 324             }
 325
 326             ret = av_append_packet(pb, packet, pkt_size);
 327             if (ret < 0)
 328                 return ret;
 329             if (endframe && packet->size > 0) {
 330                 av_packet_move_ref(pkt, packet);
 331                 pkt->pos = m->pos;
 332                 pkt->stream_index = stream_index;
 333                 if (s->streams[stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
 334                     pkt->duration = 1;
 335                     if (pkt->data[0] & 0x80)
 336                         pkt->flags |= AV_PKT_FLAG_KEY;
 337                 } else {
 338                     pkt->flags |= AV_PKT_FLAG_KEY;
 339                 }
 340                 return ret;
 341             }
 342         }
 343
 344         m->in_block = 0;
 345
 346         if (m->flags % 2 == 0) {
 347             if (m->size <= 0)
 348                 return AVERROR_INVALIDDATA;
 349             avio_seek(pb, m->pos + m->size, SEEK_SET);
 350         }
 351     }
 352
 353     return AVERROR_EOF;
 354 }
 355
 356 static int moflex_read_seek(AVFormatContext *s, int stream_index,
 357                             int64_t pts, int flags)
 358 {
 359     MOFLEXDemuxContext *m = s->priv_data;
 360
 361     m->in_block = 0;
 362
 363     return -1;
 364 }
 365
 366 static int moflex_read_close(AVFormatContext *s)
 367 {
 368     for (int i = 0; i < s->nb_streams; i++) {
 369         av_packet_free((AVPacket **)&s->streams[i]->priv_data);
 370     }
 371
 372     return 0;
 373 }
 374
 375 const FFInputFormat ff_moflex_demuxer = {
 376     .p.name         = "moflex",
 377     .p.long_name    = NULL_IF_CONFIG_SMALL("MobiClip MOFLEX"),
 378     .p.extensions   = "moflex",
 379     .p.flags        = AVFMT_GENERIC_INDEX,
 380     .priv_data_size = sizeof(MOFLEXDemuxContext),
 381     .read_probe     = moflex_probe,
 382     .read_header    = moflex_read_header,
 383     .read_packet    = moflex_read_packet,
 384     .read_seek      = moflex_read_seek,
 385     .read_close     = moflex_read_close,
 386     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
 387 };