1 /*
2 * Xiph CELT decoder using libcelt
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
22 #include <celt/celt.h>
23 #include <celt/celt_header.h>
24 #include "avcodec.h"
25 #include "codec_internal.h"
26 #include "internal.h"
27 #include "libavutil/intreadwrite.h"
28
29 struct libcelt_context {
30 CELTMode *mode;
31 CELTDecoder *dec;
32 int discard;
33 };
34
ff_celt_error_to_averror(int err)35 static int ff_celt_error_to_averror(int err)
36 {
37 switch (err) {
38 case CELT_BAD_ARG: return AVERROR(EINVAL);
39 #ifdef CELT_BUFFER_TOO_SMALL
40 case CELT_BUFFER_TOO_SMALL: return AVERROR(ENOBUFS);
41 #endif
42 case CELT_INTERNAL_ERROR: return AVERROR(EFAULT);
43 case CELT_CORRUPTED_DATA: return AVERROR_INVALIDDATA;
44 case CELT_UNIMPLEMENTED: return AVERROR(ENOSYS);
45 #ifdef ENOTRECOVERABLE
46 case CELT_INVALID_STATE: return AVERROR(ENOTRECOVERABLE);
47 #endif
48 case CELT_ALLOC_FAIL: return AVERROR(ENOMEM);
49 default: return AVERROR(EINVAL);
50 }
51 }
52
ff_celt_bitstream_version_hack(CELTMode * mode)53 static int ff_celt_bitstream_version_hack(CELTMode *mode)
54 {
55 CELTHeader header = { .version_id = 0 };
56 celt_header_init(&header, mode, 960, 2);
57 return header.version_id;
58 }
59
libcelt_dec_init(AVCodecContext * c)60 static av_cold int libcelt_dec_init(AVCodecContext *c)
61 {
62 struct libcelt_context *celt = c->priv_data;
63 int err;
64
65 if (!c->ch_layout.nb_channels || !c->frame_size ||
66 c->frame_size > INT_MAX / sizeof(int16_t) / c->ch_layout.nb_channels)
67 return AVERROR(EINVAL);
68 celt->mode = celt_mode_create(c->sample_rate, c->frame_size, &err);
69 if (!celt->mode)
70 return ff_celt_error_to_averror(err);
71 celt->dec = celt_decoder_create_custom(celt->mode, c->ch_layout.nb_channels, &err);
72 if (!celt->dec) {
73 celt_mode_destroy(celt->mode);
74 return ff_celt_error_to_averror(err);
75 }
76 if (c->extradata_size >= 4) {
77 celt->discard = AV_RL32(c->extradata);
78 if (celt->discard < 0 || celt->discard >= c->frame_size) {
79 av_log(c, AV_LOG_WARNING,
80 "Invalid overlap (%d), ignored.\n", celt->discard);
81 celt->discard = 0;
82 }
83 }
84 if (c->extradata_size >= 8) {
85 unsigned version = AV_RL32(c->extradata + 4);
86 unsigned lib_version = ff_celt_bitstream_version_hack(celt->mode);
87 if (version != lib_version)
88 av_log(c, AV_LOG_WARNING,
89 "CELT bitstream version 0x%x may be "
90 "improperly decoded by libcelt for version 0x%x.\n",
91 version, lib_version);
92 }
93 c->sample_fmt = AV_SAMPLE_FMT_S16;
94 return 0;
95 }
96
libcelt_dec_close(AVCodecContext * c)97 static av_cold int libcelt_dec_close(AVCodecContext *c)
98 {
99 struct libcelt_context *celt = c->priv_data;
100
101 celt_decoder_destroy(celt->dec);
102 celt_mode_destroy(celt->mode);
103 return 0;
104 }
105
libcelt_dec_decode(AVCodecContext * c,AVFrame * frame,int * got_frame_ptr,AVPacket * pkt)106 static int libcelt_dec_decode(AVCodecContext *c, AVFrame *frame,
107 int *got_frame_ptr, AVPacket *pkt)
108 {
109 struct libcelt_context *celt = c->priv_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->ch_layout.nb_channels,
123 frame->nb_samples * c->ch_layout.nb_channels * sizeof(int16_t));
124 celt->discard = 0;
125 }
126 *got_frame_ptr = 1;
127 return pkt->size;
128 }
129
130 const FFCodec ff_libcelt_decoder = {
131 .p.name = "libcelt",
132 .p.long_name = NULL_IF_CONFIG_SMALL("Xiph CELT decoder using libcelt"),
133 .p.type = AVMEDIA_TYPE_AUDIO,
134 .p.id = AV_CODEC_ID_CELT,
135 .p.capabilities = AV_CODEC_CAP_DR1,
136 .p.wrapper_name = "libcelt",
137 .priv_data_size = sizeof(struct libcelt_context),
138 .init = libcelt_dec_init,
139 .close = libcelt_dec_close,
140 FF_CODEC_DECODE_CB(libcelt_dec_decode),
141 };
142