| 1 | /* |
| 2 | * Interface to libgsm for GSM encoding |
| 3 | * Copyright (c) 2005 Alban Bedel <albeu@free.fr> |
| 4 | * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be> |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * @file |
| 25 | * Interface to libgsm for GSM encoding |
| 26 | */ |
| 27 | |
| 28 | // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html |
| 29 | |
| 30 | #include "config.h" |
| 31 | #if HAVE_GSM_H |
| 32 | #include <gsm.h> |
| 33 | #else |
| 34 | #include <gsm/gsm.h> |
| 35 | #endif |
| 36 | |
| 37 | #include "libavutil/common.h" |
| 38 | |
| 39 | #include "avcodec.h" |
| 40 | #include "internal.h" |
| 41 | #include "gsm.h" |
| 42 | |
| 43 | static av_cold int libgsm_encode_close(AVCodecContext *avctx) { |
| 44 | gsm_destroy(avctx->priv_data); |
| 45 | avctx->priv_data = NULL; |
| 46 | return 0; |
| 47 | } |
| 48 | |
| 49 | static av_cold int libgsm_encode_init(AVCodecContext *avctx) { |
| 50 | if (avctx->channels > 1) { |
| 51 | av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n", |
| 52 | avctx->channels); |
| 53 | return -1; |
| 54 | } |
| 55 | |
| 56 | if (avctx->sample_rate != 8000) { |
| 57 | av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n", |
| 58 | avctx->sample_rate); |
| 59 | if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) |
| 60 | return -1; |
| 61 | } |
| 62 | if (avctx->bit_rate != 13000 /* Official */ && |
| 63 | avctx->bit_rate != 13200 /* Very common */ && |
| 64 | avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) { |
| 65 | av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %dbps\n", |
| 66 | avctx->bit_rate); |
| 67 | if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) |
| 68 | return -1; |
| 69 | } |
| 70 | |
| 71 | avctx->priv_data = gsm_create(); |
| 72 | if (!avctx->priv_data) |
| 73 | goto error; |
| 74 | |
| 75 | switch(avctx->codec_id) { |
| 76 | case AV_CODEC_ID_GSM: |
| 77 | avctx->frame_size = GSM_FRAME_SIZE; |
| 78 | avctx->block_align = GSM_BLOCK_SIZE; |
| 79 | break; |
| 80 | case AV_CODEC_ID_GSM_MS: { |
| 81 | int one = 1; |
| 82 | gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one); |
| 83 | avctx->frame_size = 2*GSM_FRAME_SIZE; |
| 84 | avctx->block_align = GSM_MS_BLOCK_SIZE; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | return 0; |
| 89 | error: |
| 90 | libgsm_encode_close(avctx); |
| 91 | return -1; |
| 92 | } |
| 93 | |
| 94 | static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
| 95 | const AVFrame *frame, int *got_packet_ptr) |
| 96 | { |
| 97 | int ret; |
| 98 | gsm_signal *samples = (gsm_signal *)frame->data[0]; |
| 99 | struct gsm_state *state = avctx->priv_data; |
| 100 | |
| 101 | if ((ret = ff_alloc_packet2(avctx, avpkt, avctx->block_align)) < 0) |
| 102 | return ret; |
| 103 | |
| 104 | switch(avctx->codec_id) { |
| 105 | case AV_CODEC_ID_GSM: |
| 106 | gsm_encode(state, samples, avpkt->data); |
| 107 | break; |
| 108 | case AV_CODEC_ID_GSM_MS: |
| 109 | gsm_encode(state, samples, avpkt->data); |
| 110 | gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32); |
| 111 | } |
| 112 | |
| 113 | *got_packet_ptr = 1; |
| 114 | return 0; |
| 115 | } |
| 116 | |
| 117 | |
| 118 | #if CONFIG_LIBGSM_ENCODER |
| 119 | AVCodec ff_libgsm_encoder = { |
| 120 | .name = "libgsm", |
| 121 | .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"), |
| 122 | .type = AVMEDIA_TYPE_AUDIO, |
| 123 | .id = AV_CODEC_ID_GSM, |
| 124 | .init = libgsm_encode_init, |
| 125 | .encode2 = libgsm_encode_frame, |
| 126 | .close = libgsm_encode_close, |
| 127 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
| 128 | AV_SAMPLE_FMT_NONE }, |
| 129 | }; |
| 130 | #endif |
| 131 | #if CONFIG_LIBGSM_MS_ENCODER |
| 132 | AVCodec ff_libgsm_ms_encoder = { |
| 133 | .name = "libgsm_ms", |
| 134 | .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"), |
| 135 | .type = AVMEDIA_TYPE_AUDIO, |
| 136 | .id = AV_CODEC_ID_GSM_MS, |
| 137 | .init = libgsm_encode_init, |
| 138 | .encode2 = libgsm_encode_frame, |
| 139 | .close = libgsm_encode_close, |
| 140 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
| 141 | AV_SAMPLE_FMT_NONE }, |
| 142 | }; |
| 143 | #endif |