Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 6147 | serge | 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 |
||
| 23 | |||
| 24 | #include "libavutil/common.h" |
||
| 25 | #include "avcodec.h" |
||
| 26 | #include "internal.h" |
||
| 27 | #include "lpc.h" |
||
| 28 | |||
| 29 | typedef struct CNGContext { |
||
| 30 | LPCContext lpc; |
||
| 31 | int order; |
||
| 32 | int32_t *samples32; |
||
| 33 | double *ref_coef; |
||
| 34 | } CNGContext; |
||
| 35 | |||
| 36 | static av_cold int cng_encode_close(AVCodecContext *avctx) |
||
| 37 | { |
||
| 38 | CNGContext *p = avctx->priv_data; |
||
| 39 | ff_lpc_end(&p->lpc); |
||
| 40 | av_free(p->samples32); |
||
| 41 | av_free(p->ref_coef); |
||
| 42 | return 0; |
||
| 43 | } |
||
| 44 | |||
| 45 | static av_cold int cng_encode_init(AVCodecContext *avctx) |
||
| 46 | { |
||
| 47 | CNGContext *p = avctx->priv_data; |
||
| 48 | int ret; |
||
| 49 | |||
| 50 | if (avctx->channels != 1) { |
||
| 51 | av_log(avctx, AV_LOG_ERROR, "Only mono supported\n"); |
||
| 52 | return AVERROR(EINVAL); |
||
| 53 | } |
||
| 54 | |||
| 55 | avctx->frame_size = 640; |
||
| 56 | p->order = 10; |
||
| 57 | if ((ret = ff_lpc_init(&p->lpc, avctx->frame_size, p->order, FF_LPC_TYPE_LEVINSON)) < 0) |
||
| 58 | return ret; |
||
| 59 | p->samples32 = av_malloc_array(avctx->frame_size, sizeof(*p->samples32)); |
||
| 60 | p->ref_coef = av_malloc_array(p->order, sizeof(*p->ref_coef)); |
||
| 61 | if (!p->samples32 || !p->ref_coef) { |
||
| 62 | cng_encode_close(avctx); |
||
| 63 | return AVERROR(ENOMEM); |
||
| 64 | } |
||
| 65 | |||
| 66 | return 0; |
||
| 67 | } |
||
| 68 | |||
| 69 | static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
||
| 70 | const AVFrame *frame, int *got_packet_ptr) |
||
| 71 | { |
||
| 72 | CNGContext *p = avctx->priv_data; |
||
| 73 | int ret, i; |
||
| 74 | double energy = 0; |
||
| 75 | int qdbov; |
||
| 76 | int16_t *samples = (int16_t*) frame->data[0]; |
||
| 77 | |||
| 78 | if ((ret = ff_alloc_packet2(avctx, avpkt, 1 + p->order, 1 + p->order))) { |
||
| 79 | av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n"); |
||
| 80 | return ret; |
||
| 81 | } |
||
| 82 | |||
| 83 | for (i = 0; i < frame->nb_samples; i++) { |
||
| 84 | p->samples32[i] = samples[i]; |
||
| 85 | energy += samples[i] * samples[i]; |
||
| 86 | } |
||
| 87 | energy /= frame->nb_samples; |
||
| 88 | if (energy > 0) { |
||
| 89 | double dbov = 10 * log10(energy / 1081109975); |
||
| 90 | qdbov = av_clip_uintp2(-floor(dbov), 7); |
||
| 91 | } else { |
||
| 92 | qdbov = 127; |
||
| 93 | } |
||
| 94 | ret = ff_lpc_calc_ref_coefs(&p->lpc, p->samples32, p->order, p->ref_coef); |
||
| 95 | avpkt->data[0] = qdbov; |
||
| 96 | for (i = 0; i < p->order; i++) |
||
| 97 | avpkt->data[1 + i] = p->ref_coef[i] * 127 + 127; |
||
| 98 | |||
| 99 | *got_packet_ptr = 1; |
||
| 100 | av_assert1(avpkt->size == 1 + p->order); |
||
| 101 | |||
| 102 | return 0; |
||
| 103 | } |
||
| 104 | |||
| 105 | AVCodec ff_comfortnoise_encoder = { |
||
| 106 | .name = "comfortnoise", |
||
| 107 | .long_name = NULL_IF_CONFIG_SMALL("RFC 3389 comfort noise generator"), |
||
| 108 | .type = AVMEDIA_TYPE_AUDIO, |
||
| 109 | .id = AV_CODEC_ID_COMFORT_NOISE, |
||
| 110 | .priv_data_size = sizeof(CNGContext), |
||
| 111 | .init = cng_encode_init, |
||
| 112 | .encode2 = cng_encode_frame, |
||
| 113 | .close = cng_encode_close, |
||
| 114 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
||
| 115 | AV_SAMPLE_FMT_NONE }, |
||
| 116 | }; |