/libavformat/oggparsecelt.c

http://github.com/FFmpeg/FFmpeg · C · 97 lines · 62 code · 11 blank · 24 comment · 10 complexity · 9021ad80a89fbc75d65dc15c4f07b716 MD5 · raw file

  1. /*
  2. * Xiph CELT parser for Ogg
  3. * Copyright (c) 2011 Nicolas George
  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. #include <string.h>
  22. #include "libavutil/intreadwrite.h"
  23. #include "avformat.h"
  24. #include "internal.h"
  25. #include "oggdec.h"
  26. struct oggcelt_private {
  27. int extra_headers_left;
  28. };
  29. static int celt_header(AVFormatContext *s, int idx)
  30. {
  31. struct ogg *ogg = s->priv_data;
  32. struct ogg_stream *os = ogg->streams + idx;
  33. AVStream *st = s->streams[idx];
  34. struct oggcelt_private *priv = os->private;
  35. uint8_t *p = os->buf + os->pstart;
  36. int ret;
  37. if (os->psize == 60 &&
  38. !memcmp(p, ff_celt_codec.magic, ff_celt_codec.magicsize)) {
  39. /* Main header */
  40. uint32_t version, sample_rate, nb_channels;
  41. uint32_t overlap, extra_headers;
  42. priv = av_malloc(sizeof(struct oggcelt_private));
  43. if (!priv)
  44. return AVERROR(ENOMEM);
  45. ret = ff_alloc_extradata(st->codecpar, 2 * sizeof(uint32_t));
  46. if (ret < 0) {
  47. av_free(priv);
  48. return ret;
  49. }
  50. version = AV_RL32(p + 28);
  51. /* unused header size field skipped */
  52. sample_rate = AV_RL32(p + 36);
  53. nb_channels = AV_RL32(p + 40);
  54. overlap = AV_RL32(p + 48);
  55. /* unused bytes per packet field skipped */
  56. extra_headers = AV_RL32(p + 56);
  57. st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  58. st->codecpar->codec_id = AV_CODEC_ID_CELT;
  59. st->codecpar->sample_rate = sample_rate;
  60. st->codecpar->channels = nb_channels;
  61. if (sample_rate)
  62. avpriv_set_pts_info(st, 64, 1, sample_rate);
  63. if (os->private) {
  64. av_free(priv);
  65. priv = os->private;
  66. }
  67. os->private = priv;
  68. priv->extra_headers_left = 1 + extra_headers;
  69. AV_WL32(st->codecpar->extradata + 0, overlap);
  70. AV_WL32(st->codecpar->extradata + 4, version);
  71. return 1;
  72. } else if (priv && priv->extra_headers_left) {
  73. /* Extra headers (vorbiscomment) */
  74. ff_vorbis_stream_comment(s, st, p, os->psize);
  75. priv->extra_headers_left--;
  76. return 1;
  77. } else {
  78. return 0;
  79. }
  80. }
  81. const struct ogg_codec ff_celt_codec = {
  82. .magic = "CELT ",
  83. .magicsize = 8,
  84. .header = celt_header,
  85. .nb_header = 2,
  86. };