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 28struct libcelt_context { 29 CELTMode *mode; 30 CELTDecoder *dec; 31 int discard; 32}; 33 34static 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 52static 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 59static 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 96static 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 105static 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 130AVCodec 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}; 141