| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * RFC 3389 comfort noise generator | ||
| 3 | * Copyright (c) 2012 Martin Storsjo | ||
| 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 <math.h> | ||
| 23 | |||
| 24 | #include "libavutil/avassert.h" | ||
| 25 | #include "libavutil/common.h" | ||
| 26 | #include "libavutil/mem.h" | ||
| 27 | #include "avcodec.h" | ||
| 28 | #include "codec_internal.h" | ||
| 29 | #include "encode.h" | ||
| 30 | #include "lpc.h" | ||
| 31 | |||
| 32 | typedef struct CNGContext { | ||
| 33 | LPCContext lpc; | ||
| 34 | int order; | ||
| 35 | int32_t *samples32; | ||
| 36 | double *ref_coef; | ||
| 37 | } CNGContext; | ||
| 38 | |||
| 39 | ✗ | static av_cold int cng_encode_close(AVCodecContext *avctx) | |
| 40 | { | ||
| 41 | ✗ | CNGContext *p = avctx->priv_data; | |
| 42 | ✗ | ff_lpc_end(&p->lpc); | |
| 43 | ✗ | av_freep(&p->samples32); | |
| 44 | ✗ | av_freep(&p->ref_coef); | |
| 45 | ✗ | return 0; | |
| 46 | } | ||
| 47 | |||
| 48 | ✗ | static av_cold int cng_encode_init(AVCodecContext *avctx) | |
| 49 | { | ||
| 50 | ✗ | CNGContext *p = avctx->priv_data; | |
| 51 | int ret; | ||
| 52 | |||
| 53 | ✗ | avctx->frame_size = 640; | |
| 54 | ✗ | p->order = 10; | |
| 55 | ✗ | if ((ret = ff_lpc_init(&p->lpc, avctx->frame_size, p->order, FF_LPC_TYPE_LEVINSON)) < 0) | |
| 56 | ✗ | return ret; | |
| 57 | ✗ | p->samples32 = av_malloc_array(avctx->frame_size, sizeof(*p->samples32)); | |
| 58 | ✗ | p->ref_coef = av_malloc_array(p->order, sizeof(*p->ref_coef)); | |
| 59 | ✗ | if (!p->samples32 || !p->ref_coef) | |
| 60 | ✗ | return AVERROR(ENOMEM); | |
| 61 | |||
| 62 | ✗ | return 0; | |
| 63 | } | ||
| 64 | |||
| 65 | ✗ | static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, | |
| 66 | const AVFrame *frame, int *got_packet_ptr) | ||
| 67 | { | ||
| 68 | ✗ | CNGContext *p = avctx->priv_data; | |
| 69 | int ret, i; | ||
| 70 | ✗ | double energy = 0; | |
| 71 | int qdbov; | ||
| 72 | ✗ | const int16_t *samples = (const int16_t*) frame->data[0]; | |
| 73 | |||
| 74 | ✗ | if ((ret = ff_get_encode_buffer(avctx, avpkt, 1 + p->order, 0))) { | |
| 75 | ✗ | av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n"); | |
| 76 | ✗ | return ret; | |
| 77 | } | ||
| 78 | |||
| 79 | ✗ | for (i = 0; i < frame->nb_samples; i++) { | |
| 80 | ✗ | p->samples32[i] = samples[i]; | |
| 81 | ✗ | energy += samples[i] * samples[i]; | |
| 82 | } | ||
| 83 | ✗ | energy /= frame->nb_samples; | |
| 84 | ✗ | if (energy > 0) { | |
| 85 | ✗ | double dbov = 10 * log10(energy / 1081109975); | |
| 86 | ✗ | qdbov = av_clip_uintp2(-floor(dbov), 7); | |
| 87 | } else { | ||
| 88 | ✗ | qdbov = 127; | |
| 89 | } | ||
| 90 | ✗ | ff_lpc_calc_ref_coefs(&p->lpc, p->samples32, p->order, p->ref_coef); | |
| 91 | ✗ | avpkt->data[0] = qdbov; | |
| 92 | ✗ | for (i = 0; i < p->order; i++) | |
| 93 | ✗ | avpkt->data[1 + i] = p->ref_coef[i] * 127 + 127; | |
| 94 | |||
| 95 | ✗ | *got_packet_ptr = 1; | |
| 96 | av_assert1(avpkt->size == 1 + p->order); | ||
| 97 | |||
| 98 | ✗ | return 0; | |
| 99 | } | ||
| 100 | |||
| 101 | const FFCodec ff_comfortnoise_encoder = { | ||
| 102 | .p.name = "comfortnoise", | ||
| 103 | CODEC_LONG_NAME("RFC 3389 comfort noise generator"), | ||
| 104 | .p.type = AVMEDIA_TYPE_AUDIO, | ||
| 105 | .p.id = AV_CODEC_ID_COMFORT_NOISE, | ||
| 106 | .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE, | ||
| 107 | .priv_data_size = sizeof(CNGContext), | ||
| 108 | .init = cng_encode_init, | ||
| 109 | FF_CODEC_ENCODE_CB(cng_encode_frame), | ||
| 110 | .close = cng_encode_close, | ||
| 111 | .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, | ||
| 112 | AV_SAMPLE_FMT_NONE }, | ||
| 113 | .p.ch_layouts = (const AVChannelLayout[]){ AV_CHANNEL_LAYOUT_MONO, { 0 } }, | ||
| 114 | .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, | ||
| 115 | }; | ||
| 116 |