FFmpeg: libavcodec/libcelt_dec.c Source File

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libavcodec

libcelt_dec.c

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1 /*

2 * Xiph CELT decoder using libcelt

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 */

22 #include <celt/celt.h>

23 #include <celt/celt_header.h>

24 #include "avcodec.h"

25 #include "internal.h"

26 #include "libavutil/intreadwrite.h"

28 struct libcelt_context {

29 CELTMode *mode;

30 CELTDecoder *dec;

31 int discard;

32 };

34 static int ff_celt_error_to_averror(int err)

35 {

36 switch (err) {

37 case CELT_BAD_ARG: return AVERROR(EINVAL);

38 #ifdef CELT_BUFFER_TOO_SMALL

39 case CELT_BUFFER_TOO_SMALL: return AVERROR(ENOBUFS);

40 #endif

41 case CELT_INTERNAL_ERROR: return AVERROR(EFAULT);

42 case CELT_CORRUPTED_DATA: return AVERROR_INVALIDDATA;

43 case CELT_UNIMPLEMENTED: return AVERROR(ENOSYS);

44 #ifdef ENOTRECOVERABLE

45 case CELT_INVALID_STATE: return AVERROR(ENOTRECOVERABLE);

46 #endif

47 case CELT_ALLOC_FAIL: return AVERROR(ENOMEM);

48 default: return AVERROR(EINVAL);

49 }

50 }

52 static int ff_celt_bitstream_version_hack(CELTMode *mode)

53 {

54 CELTHeader header = { .version_id = 0 };

55 celt_header_init(&header, mode, 960, 2);

56 return header.version_id;

57 }

59 static av_cold int libcelt_dec_init(AVCodecContext *c)

60 {

61 struct libcelt_context *celt = c->priv_data;

62 int err;

64 if (!c->channels || !c->frame_size ||

65 c->frame_size > INT_MAX / sizeof(int16_t) / c->channels)

66 return AVERROR(EINVAL);

67 celt->mode = celt_mode_create(c->sample_rate, c->frame_size, &err);

68 if (!celt->mode)

69 return ff_celt_error_to_averror(err);

70 celt->dec = celt_decoder_create_custom(celt->mode, c->channels, &err);

71 if (!celt->dec) {

72 celt_mode_destroy(celt->mode);

73 return ff_celt_error_to_averror(err);

74 }

75 if (c->extradata_size >= 4) {

76 celt->discard = AV_RL32(c->extradata);

77 if (celt->discard < 0 || celt->discard >= c->frame_size) {

78 av_log(c, AV_LOG_WARNING,

79 "Invalid overlap (%d), ignored.\n", celt->discard);

80 celt->discard = 0;

81 }

82 }

83 if (c->extradata_size >= 8) {

84 unsigned version = AV_RL32(c->extradata + 4);

85 unsigned lib_version = ff_celt_bitstream_version_hack(celt->mode);

86 if (version != lib_version)

87 av_log(c, AV_LOG_WARNING,

88 "CELT bitstream version 0x%x may be "

89 "improperly decoded by libcelt for version 0x%x.\n",

90 version, lib_version);

91 }

92 c->sample_fmt = AV_SAMPLE_FMT_S16;

93 return 0;

94 }

96 static av_cold int libcelt_dec_close(AVCodecContext *c)

97 {

98 struct libcelt_context *celt = c->priv_data;

100 celt_decoder_destroy(celt->dec);

101 celt_mode_destroy(celt->mode);

102 return 0;

103 }

104

105 static int libcelt_dec_decode(AVCodecContext *c, void *data,

106 int *got_frame_ptr, AVPacket *pkt)

107 {

108 struct libcelt_context *celt = c->priv_data;

109 AVFrame *frame = data;

110 int err;

111 int16_t *pcm;

112

113 frame->nb_samples = c->frame_size;

114 if ((err = ff_get_buffer(c, frame, 0)) < 0)

115 return err;

116 pcm = (int16_t *)frame->data[0];

117 err = celt_decode(celt->dec, pkt->data, pkt->size, pcm, c->frame_size);

118 if (err < 0)

119 return ff_celt_error_to_averror(err);

120 if (celt->discard) {

121 frame->nb_samples -= celt->discard;

122 memmove(pcm, pcm + celt->discard * c->channels,

123 frame->nb_samples * c->channels * sizeof(int16_t));

124 celt->discard = 0;

125 }

126 *got_frame_ptr = 1;

127 return pkt->size;

128 }

129

130 AVCodec ff_libcelt_decoder = {

131 .name = "libcelt",

132 .type = AVMEDIA_TYPE_AUDIO,

133 .id = AV_CODEC_ID_CELT,

134 .priv_data_size = sizeof(struct libcelt_context),

135 .init = libcelt_dec_init,

136 .close = libcelt_dec_close,

137 .decode = libcelt_dec_decode,

138 .capabilities = CODEC_CAP_DR1,

139 .long_name = NULL_IF_CONFIG_SMALL("Xiph CELT decoder using libcelt"),

140 };

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