libavformat/oggparsevorbis.c

   1 /**
   2       Copyright (C) 2005  Michael Ahlberg, Måns Rullgård
   3
   4       Permission is hereby granted, free of charge, to any person
   5       obtaining a copy of this software and associated documentation
   6       files (the "Software"), to deal in the Software without
   7       restriction, including without limitation the rights to use, copy,
   8       modify, merge, publish, distribute, sublicense, and/or sell copies
   9       of the Software, and to permit persons to whom the Software is
  10       furnished to do so, subject to the following conditions:
  11
  12       The above copyright notice and this permission notice shall be
  13       included in all copies or substantial portions of the Software.
  14
  15       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16       EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18       NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  19       HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  20       WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21       OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22       DEALINGS IN THE SOFTWARE.
  23 **/
  24
  25 #include <stdlib.h>
  26 #include "libavutil/avstring.h"
  27 #include "libavutil/bswap.h"
  28 #include "libavcodec/get_bits.h"
  29 #include "libavcodec/bytestream.h"
  30 #include "avformat.h"
  31 #include "oggdec.h"
  32
  33 int
  34 vorbis_comment(AVFormatContext * as, uint8_t *buf, int size)
  35 {
  36     const uint8_t *p = buf;
  37     const uint8_t *end = buf + size;
  38     unsigned s, n, j;
  39
  40     if (size < 8) /* must have vendor_length and user_comment_list_length */
  41         return -1;
  42
  43     s = bytestream_get_le32(&p);
  44
  45     if (end - p < s)
  46         return -1;
  47
  48     p += s;
  49
  50     n = bytestream_get_le32(&p);
  51
  52     while (p < end && n > 0) {
  53         const char *t, *v;
  54         int tl, vl;
  55
  56         s = bytestream_get_le32(&p);
  57
  58         if (end - p < s)
  59             break;
  60
  61         t = p;
  62         p += s;
  63         n--;
  64
  65         v = memchr(t, '=', s);
  66         if (!v)
  67             continue;
  68
  69         tl = v - t;
  70         vl = s - tl - 1;
  71         v++;
  72
  73         if (tl && vl) {
  74             char *tt, *ct;
  75
  76             tt = av_malloc(tl + 1);
  77             ct = av_malloc(vl + 1);
  78             if (!tt || !ct) {
  79                 av_freep(&tt);
  80                 av_freep(&ct);
  81                 av_log(as, AV_LOG_WARNING, "out-of-memory error. skipping VorbisComment tag.\n");
  82                 continue;
  83             }
  84
  85             for (j = 0; j < tl; j++)
  86                 tt[j] = toupper(t[j]);
  87             tt[tl] = 0;
  88
  89             memcpy(ct, v, vl);
  90             ct[vl] = 0;
  91
  92             av_metadata_set(&as->metadata, tt, ct);
  93
  94             av_freep(&tt);
  95             av_freep(&ct);
  96         }
  97     }
  98
  99     if (p != end)
 100         av_log(as, AV_LOG_INFO, "%ti bytes of comment header remain\n", p-end);
 101     if (n > 0)
 102         av_log(as, AV_LOG_INFO,
 103                "truncated comment header, %i comments not found\n", n);
 104
 105     return 0;
 106 }
 107
 108
 109 /** Parse the vorbis header
 110  * Vorbis Identification header from Vorbis_I_spec.html#vorbis-spec-codec
 111  * [vorbis_version] = read 32 bits as unsigned integer | Not used
 112  * [audio_channels] = read 8 bit integer as unsigned | Used
 113  * [audio_sample_rate] = read 32 bits as unsigned integer | Used
 114  * [bitrate_maximum] = read 32 bits as signed integer | Not used yet
 115  * [bitrate_nominal] = read 32 bits as signed integer | Not used yet
 116  * [bitrate_minimum] = read 32 bits as signed integer | Used as bitrate
 117  * [blocksize_0] = read 4 bits as unsigned integer | Not Used
 118  * [blocksize_1] = read 4 bits as unsigned integer | Not Used
 119  * [framing_flag] = read one bit | Not Used
 120  *    */
 121
 122 struct oggvorbis_private {
 123     unsigned int len[3];
 124     unsigned char *packet[3];
 125 };
 126
 127
 128 static unsigned int
 129 fixup_vorbis_headers(AVFormatContext * as, struct oggvorbis_private *priv,
 130                      uint8_t **buf)
 131 {
 132     int i,offset, len;
 133     unsigned char *ptr;
 134
 135     len = priv->len[0] + priv->len[1] + priv->len[2];
 136     ptr = *buf = av_mallocz(len + len/255 + 64);
 137
 138     ptr[0] = 2;
 139     offset = 1;
 140     offset += av_xiphlacing(&ptr[offset], priv->len[0]);
 141     offset += av_xiphlacing(&ptr[offset], priv->len[1]);
 142     for (i = 0; i < 3; i++) {
 143         memcpy(&ptr[offset], priv->packet[i], priv->len[i]);
 144         offset += priv->len[i];
 145     }
 146     *buf = av_realloc(*buf, offset + FF_INPUT_BUFFER_PADDING_SIZE);
 147     return offset;
 148 }
 149
 150
 151 static int
 152 vorbis_header (AVFormatContext * s, int idx)
 153 {
 154     struct ogg *ogg = s->priv_data;
 155     struct ogg_stream *os = ogg->streams + idx;
 156     AVStream *st = s->streams[idx];
 157     struct oggvorbis_private *priv;
 158
 159     if (os->seq > 2)
 160         return 0;
 161
 162     if (os->seq == 0) {
 163         os->private = av_mallocz(sizeof(struct oggvorbis_private));
 164         if (!os->private)
 165             return 0;
 166     }
 167
 168     if (os->psize < 1)
 169         return -1;
 170
 171     priv = os->private;
 172     priv->len[os->seq] = os->psize;
 173     priv->packet[os->seq] = av_mallocz(os->psize);
 174     memcpy(priv->packet[os->seq], os->buf + os->pstart, os->psize);
 175     if (os->buf[os->pstart] == 1) {
 176         const uint8_t *p = os->buf + os->pstart + 7; /* skip "\001vorbis" tag */
 177         unsigned blocksize, bs0, bs1;
 178
 179         if (os->psize != 30)
 180             return -1;
 181
 182         if (bytestream_get_le32(&p) != 0) /* vorbis_version */
 183             return -1;
 184
 185         st->codec->channels = bytestream_get_byte(&p);
 186         st->codec->sample_rate = bytestream_get_le32(&p);
 187         p += 4; // skip maximum bitrate
 188         st->codec->bit_rate = bytestream_get_le32(&p); // nominal bitrate
 189         p += 4; // skip minimum bitrate
 190
 191         blocksize = bytestream_get_byte(&p);
 192         bs0 = blocksize & 15;
 193         bs1 = blocksize >> 4;
 194
 195         if (bs0 > bs1)
 196             return -1;
 197         if (bs0 < 6 || bs1 > 13)
 198             return -1;
 199
 200         if (bytestream_get_byte(&p) != 1) /* framing_flag */
 201             return -1;
 202
 203         st->codec->codec_type = CODEC_TYPE_AUDIO;
 204         st->codec->codec_id = CODEC_ID_VORBIS;
 205
 206         st->time_base.num = 1;
 207         st->time_base.den = st->codec->sample_rate;
 208     } else if (os->buf[os->pstart] == 3) {
 209         if (os->psize > 8)
 210             vorbis_comment (s, os->buf + os->pstart + 7, os->psize - 8);
 211     } else {
 212         st->codec->extradata_size =
 213             fixup_vorbis_headers(s, priv, &st->codec->extradata);
 214     }
 215
 216     return os->seq < 3;
 217 }
 218
 219 const struct ogg_codec ff_vorbis_codec = {
 220     .magic = "\001vorbis",
 221     .magicsize = 7,
 222     .header = vorbis_header
 223 };