libgsmdec: do not needlessly set *data_size to 0
[libav.git] / libavcodec / libgsm.c
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1/*
2 * Interface to libgsm for gsm encoding/decoding
3 * Copyright (c) 2005 Alban Bedel <albeu@free.fr>
346a655d 4 * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be>
bb4c2140 5 *
2912e87a 6 * This file is part of Libav.
b78e7197 7 *
2912e87a 8 * Libav is free software; you can redistribute it and/or
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9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
b78e7197 11 * version 2.1 of the License, or (at your option) any later version.
bb4c2140 12 *
2912e87a 13 * Libav is distributed in the hope that it will be useful,
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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
2912e87a 19 * License along with Libav; if not, write to the Free Software
5509bffa 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
bb4c2140 21 */
115329f1 22
bb4c2140 23/**
ba87f080 24 * @file
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25 * Interface to libgsm for gsm encoding/decoding
26 */
27
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28// The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
29
bb4c2140 30#include "avcodec.h"
3beb81e7 31#include <gsm/gsm.h>
bb4c2140 32
df3a80b5 33// gsm.h misses some essential constants
bb4c2140 34#define GSM_BLOCK_SIZE 33
346a655d 35#define GSM_MS_BLOCK_SIZE 65
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36#define GSM_FRAME_SIZE 160
37
8febd6af 38static av_cold int libgsm_encode_init(AVCodecContext *avctx) {
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39 if (avctx->channels > 1) {
40 av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
41 avctx->channels);
bb4c2140 42 return -1;
96ddaff5 43 }
ef79ef3c 44
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45 if (avctx->sample_rate != 8000) {
46 av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n",
47 avctx->sample_rate);
48 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
49 return -1;
50 }
51 if (avctx->bit_rate != 13000 /* Official */ &&
52 avctx->bit_rate != 13200 /* Very common */ &&
53 avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) {
54 av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %dbps\n",
55 avctx->bit_rate);
56 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
57 return -1;
58 }
bb4c2140 59
bb4c2140 60 avctx->priv_data = gsm_create();
115329f1 61
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62 switch(avctx->codec_id) {
63 case CODEC_ID_GSM:
64 avctx->frame_size = GSM_FRAME_SIZE;
65 avctx->block_align = GSM_BLOCK_SIZE;
66 break;
67 case CODEC_ID_GSM_MS: {
68 int one = 1;
69 gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one);
70 avctx->frame_size = 2*GSM_FRAME_SIZE;
71 avctx->block_align = GSM_MS_BLOCK_SIZE;
72 }
73 }
74
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75 avctx->coded_frame= avcodec_alloc_frame();
76 avctx->coded_frame->key_frame= 1;
115329f1 77
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78 return 0;
79}
80
8febd6af 81static av_cold int libgsm_encode_close(AVCodecContext *avctx) {
916ff022 82 av_freep(&avctx->coded_frame);
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83 gsm_destroy(avctx->priv_data);
84 avctx->priv_data = NULL;
85 return 0;
86}
87
88static int libgsm_encode_frame(AVCodecContext *avctx,
89 unsigned char *frame, int buf_size, void *data) {
90 // we need a full block
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91 if(buf_size < avctx->block_align) return 0;
92
93 switch(avctx->codec_id) {
94 case CODEC_ID_GSM:
95 gsm_encode(avctx->priv_data,data,frame);
96 break;
97 case CODEC_ID_GSM_MS:
98 gsm_encode(avctx->priv_data,data,frame);
99 gsm_encode(avctx->priv_data,((short*)data)+GSM_FRAME_SIZE,frame+32);
100 }
101 return avctx->block_align;
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102}
103
104
d36beb3f 105AVCodec ff_libgsm_encoder = {
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106 .name = "libgsm",
107 .type = AVMEDIA_TYPE_AUDIO,
108 .id = CODEC_ID_GSM,
8febd6af 109 .init = libgsm_encode_init,
ec6402b7 110 .encode = libgsm_encode_frame,
8febd6af 111 .close = libgsm_encode_close,
5d6e4c16 112 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
fe4bf374 113 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
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114};
115
d36beb3f 116AVCodec ff_libgsm_ms_encoder = {
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117 .name = "libgsm_ms",
118 .type = AVMEDIA_TYPE_AUDIO,
119 .id = CODEC_ID_GSM_MS,
8febd6af 120 .init = libgsm_encode_init,
ec6402b7 121 .encode = libgsm_encode_frame,
8febd6af 122 .close = libgsm_encode_close,
5d6e4c16 123 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
fe4bf374 124 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
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125};
126
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127static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
128 if (avctx->channels > 1) {
129 av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
130 avctx->channels);
131 return -1;
132 }
133
134 if (!avctx->channels)
135 avctx->channels = 1;
136
137 if (!avctx->sample_rate)
138 avctx->sample_rate = 8000;
139
140 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
141
142 avctx->priv_data = gsm_create();
143
144 switch(avctx->codec_id) {
145 case CODEC_ID_GSM:
146 avctx->frame_size = GSM_FRAME_SIZE;
147 avctx->block_align = GSM_BLOCK_SIZE;
148 break;
149 case CODEC_ID_GSM_MS: {
150 int one = 1;
151 gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one);
152 avctx->frame_size = 2 * GSM_FRAME_SIZE;
153 avctx->block_align = GSM_MS_BLOCK_SIZE;
154 }
155 }
156
157 return 0;
158}
159
160static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
161 gsm_destroy(avctx->priv_data);
162 avctx->priv_data = NULL;
163 return 0;
164}
165
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166static int libgsm_decode_frame(AVCodecContext *avctx,
167 void *data, int *data_size,
7a00bbad 168 AVPacket *avpkt) {
357d0d8f 169 uint8_t *buf = avpkt->data;
7a00bbad 170 int buf_size = avpkt->size;
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171 int out_size = avctx->frame_size * av_get_bytes_per_sample(avctx->sample_fmt);
172
173 if (*data_size < out_size) {
174 av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
175 return AVERROR(EINVAL);
176 }
177
202aca67 178 if(buf_size < avctx->block_align) return -1;
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179 switch(avctx->codec_id) {
180 case CODEC_ID_GSM:
181 if(gsm_decode(avctx->priv_data,buf,data)) return -1;
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182 break;
183 case CODEC_ID_GSM_MS:
184 if(gsm_decode(avctx->priv_data,buf,data) ||
185 gsm_decode(avctx->priv_data,buf+33,((int16_t*)data)+GSM_FRAME_SIZE)) return -1;
346a655d 186 }
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187
188 *data_size = out_size;
346a655d 189 return avctx->block_align;
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190}
191
d36beb3f 192AVCodec ff_libgsm_decoder = {
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193 .name = "libgsm",
194 .type = AVMEDIA_TYPE_AUDIO,
195 .id = CODEC_ID_GSM,
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196 .init = libgsm_decode_init,
197 .close = libgsm_decode_close,
ec6402b7 198 .decode = libgsm_decode_frame,
fe4bf374 199 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
bb4c2140 200};
346a655d 201
d36beb3f 202AVCodec ff_libgsm_ms_decoder = {
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203 .name = "libgsm_ms",
204 .type = AVMEDIA_TYPE_AUDIO,
205 .id = CODEC_ID_GSM_MS,
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206 .init = libgsm_decode_init,
207 .close = libgsm_decode_close,
ec6402b7 208 .decode = libgsm_decode_frame,
fe4bf374 209 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
346a655d 210};