137 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			137 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Xiph CELT / Opus decoder using libcelt
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|  * Copyright (c) 2011 Nicolas George
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| #include <celt/celt.h>
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| #include <celt/celt_header.h>
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| #include "avcodec.h"
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| #include "libavutil/intreadwrite.h"
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| 
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| struct libcelt_context {
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|     CELTMode *mode;
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|     CELTDecoder *dec;
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|     int frame_bytes;
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|     int discard;
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| };
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| 
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| static int ff_celt_error_to_averror(int err)
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| {
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|     switch(err) {
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|         case CELT_BAD_ARG:          return AVERROR(EINVAL);
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| #ifdef CELT_BUFFER_TOO_SMALL
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|         case CELT_BUFFER_TOO_SMALL: return AVERROR(ENOBUFS);
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| #endif
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|         case CELT_INTERNAL_ERROR:   return AVERROR(EFAULT);
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|         case CELT_CORRUPTED_DATA:   return AVERROR_INVALIDDATA;
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|         case CELT_UNIMPLEMENTED:    return AVERROR(ENOTSUP);
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| #ifdef ENOTRECOVERABLE
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|         case CELT_INVALID_STATE:    return AVERROR(ENOTRECOVERABLE);
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| #endif
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|         case CELT_ALLOC_FAIL:       return AVERROR(ENOMEM);
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|         default:                    return AVERROR(EINVAL);
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|     }
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| }
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| 
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| static int ff_celt_bitstream_version_hack(CELTMode *mode)
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| {
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|     CELTHeader header = { .version_id = 0 };
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|     celt_header_init(&header, mode, 960, 2);
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|     return header.version_id;
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| }
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| 
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| static av_cold int libcelt_dec_init(AVCodecContext *c)
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| {
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|     struct libcelt_context *celt = c->priv_data;
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|     int err;
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| 
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|     if (!c->channels || !c->frame_size ||
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|         c->frame_size > INT_MAX / sizeof(int16_t) / c->channels)
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|         return AVERROR(EINVAL);
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|     celt->frame_bytes = c->frame_size * c->channels * sizeof(int16_t);
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|     celt->mode = celt_mode_create(c->sample_rate, c->frame_size, &err);
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|     if (!celt->mode)
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|         return ff_celt_error_to_averror(err);
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|     celt->dec = celt_decoder_create_custom(celt->mode, c->channels, &err);
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|     if (!celt->dec) {
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|         celt_mode_destroy(celt->mode);
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|         return ff_celt_error_to_averror(err);
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|     }
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|     if (c->extradata_size >= 4) {
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|         celt->discard = AV_RL32(c->extradata);
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|         if (celt->discard < 0 || celt->discard >= c->frame_size) {
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|             av_log(c, AV_LOG_WARNING,
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|                    "Invalid overlap (%d), ignored.\n", celt->discard);
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|             celt->discard = 0;
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|         }
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|         celt->discard *= c->channels * sizeof(int16_t);
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|     }
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|     if(c->extradata_size >= 8) {
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|         unsigned version = AV_RL32(c->extradata + 4);
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|         unsigned lib_version = ff_celt_bitstream_version_hack(celt->mode);
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|         if (version != lib_version)
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|             av_log(c, AV_LOG_WARNING,
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|                    "CELT bitstream version 0x%x may be "
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|                    "improperly decoded by libcelt for version 0x%x.\n",
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|                    version, lib_version);
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|     }
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|     return 0;
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| }
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| 
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| static av_cold int libcelt_dec_close(AVCodecContext *c)
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| {
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|     struct libcelt_context *celt = c->priv_data;
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| 
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|     celt_decoder_destroy(celt->dec);
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|     celt_mode_destroy(celt->mode);
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|     return 0;
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| }
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| 
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| static int libcelt_dec_decode(AVCodecContext *c, void *pcm, int *pcm_size,
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|                               AVPacket *pkt)
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| {
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|     struct libcelt_context *celt = c->priv_data;
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|     int err;
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| 
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|     if (*pcm_size < celt->frame_bytes)
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|         return AVERROR(ENOBUFS);
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|     err = celt_decode(celt->dec, pkt->data, pkt->size, pcm, c->frame_size);
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|     if (err < 0)
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|         return ff_celt_error_to_averror(err);
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|     *pcm_size = celt->frame_bytes;
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|     if (celt->discard) {
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|         *pcm_size = celt->frame_bytes - celt->discard;
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|         memmove(pcm, (char *)pcm + celt->discard, *pcm_size);
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|         celt->discard = 0;
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|     }
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|     return pkt->size;
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| }
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| 
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| AVCodec ff_libcelt_decoder = {
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|     .name           = "libcelt",
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|     .type           = AVMEDIA_TYPE_AUDIO,
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|     .id             = CODEC_ID_CELT,
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|     .priv_data_size = sizeof(struct libcelt_context),
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|     .init           = libcelt_dec_init,
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|     .close          = libcelt_dec_close,
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|     .decode         = libcelt_dec_decode,
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|     .capabilities   = 0,
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|     .long_name = NULL_IF_CONFIG_SMALL("Xiph CELT/Opus decoder using libcelt"),
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| };
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