| 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 "internal.h" |
| 26 | #include "libavutil/intreadwrite.h" |
| 27 | |
| 28 | struct libcelt_context { |
| 29 | CELTMode *mode; |
| 30 | CELTDecoder *dec; |
| 31 | int discard; |
| 32 | }; |
| 33 | |
| 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 | } |
| 51 | |
| 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 | } |
| 58 | |
| 59 | static av_cold int libcelt_dec_init(AVCodecContext *c) |
| 60 | { |
| 61 | struct libcelt_context *celt = c->priv_data; |
| 62 | int err; |
| 63 | |
| 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 | } |
| 95 | |
| 96 | static av_cold int libcelt_dec_close(AVCodecContext *c) |
| 97 | { |
| 98 | struct libcelt_context *celt = c->priv_data; |
| 99 | |
| 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 | .long_name = NULL_IF_CONFIG_SMALL("Xiph CELT decoder using libcelt"), |
| 133 | .type = AVMEDIA_TYPE_AUDIO, |
| 134 | .id = AV_CODEC_ID_CELT, |
| 135 | .priv_data_size = sizeof(struct libcelt_context), |
| 136 | .init = libcelt_dec_init, |
| 137 | .close = libcelt_dec_close, |
| 138 | .decode = libcelt_dec_decode, |
| 139 | .capabilities = CODEC_CAP_DR1, |
| 140 | }; |