FFmpeg: libavcodec/libilbc.c Source File

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libavcodec

libilbc.c

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1 /*

2 * iLBC decoder/encoder stub

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 */

22 #include <ilbc.h>

24 #include "libavutil/channel_layout.h"

25 #include "libavutil/common.h"

26 #include "libavutil/opt.h"

27 #include "avcodec.h"

28 #include "internal.h"

30 static int get_mode(AVCodecContext *avctx)

31 {

32 if (avctx->block_align == 38)

33 return 20;

34 else if (avctx->block_align == 50)

35 return 30;

36 else if (avctx->bit_rate > 0)

37 return avctx->bit_rate <= 14000 ? 30 : 20;

38 else

39 return -1;

40 }

42 typedef struct ILBCDecContext {

43 const AVClass *class;

44 iLBC_Dec_Inst_t decoder;

45 int enhance;

46 } ILBCDecContext;

48 static const AVOption ilbc_dec_options[] = {

49 { "enhance", "Enhance the decoded audio (adds delay)", offsetof(ILBCDecContext, enhance), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM },

50 { NULL }

51 };

53 static const AVClass ilbc_dec_class = {

54 .class_name = "libilbc",

55 .item_name = av_default_item_name,

56 .option = ilbc_dec_options,

57 .version = LIBAVUTIL_VERSION_INT,

58 };

60 static av_cold int ilbc_decode_init(AVCodecContext *avctx)

61 {

62 ILBCDecContext *s = avctx->priv_data;

63 int mode;

65 if ((mode = get_mode(avctx)) < 0) {

66 av_log(avctx, AV_LOG_ERROR, "iLBC frame mode not indicated\n");

67 return AVERROR(EINVAL);

68 }

70 WebRtcIlbcfix_InitDecode(&s->decoder, mode, s->enhance);

72 avctx->channels = 1;

73 avctx->channel_layout = AV_CH_LAYOUT_MONO;

74 avctx->sample_rate = 8000;

75 avctx->sample_fmt = AV_SAMPLE_FMT_S16;

77 return 0;

78 }

80 static int ilbc_decode_frame(AVCodecContext *avctx, void *data,

81 int *got_frame_ptr, AVPacket *avpkt)

82 {

83 const uint8_t *buf = avpkt->data;

84 int buf_size = avpkt->size;

85 ILBCDecContext *s = avctx->priv_data;

86 AVFrame *frame = data;

87 int ret;

89 if (s->decoder.no_of_bytes > buf_size) {

90 av_log(avctx, AV_LOG_ERROR, "iLBC frame too short (%u, should be %u)\n",

91 buf_size, s->decoder.no_of_bytes);

92 return AVERROR_INVALIDDATA;

93 }

95 frame->nb_samples = s->decoder.blockl;

96 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

97 return ret;

99 WebRtcIlbcfix_DecodeImpl((int16_t *) frame->data[0], (const uint16_t *) buf, &s->decoder, 1);

100

101 *got_frame_ptr = 1;

102

103 return s->decoder.no_of_bytes;

104 }

105

106 AVCodec ff_libilbc_decoder = {

107 .name = "libilbc",

108 .long_name = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),

109 .type = AVMEDIA_TYPE_AUDIO,

110 .id = AV_CODEC_ID_ILBC,

111 .priv_data_size = sizeof(ILBCDecContext),

112 .init = ilbc_decode_init,

113 .decode = ilbc_decode_frame,

114 .capabilities = CODEC_CAP_DR1,

115 .priv_class = &ilbc_dec_class,

116 };

117

118 typedef struct ILBCEncContext {

119 const AVClass *class;

120 iLBC_Enc_Inst_t encoder;

121 int mode;

122 } ILBCEncContext;

123

124 static const AVOption ilbc_enc_options[] = {

125 { "mode", "iLBC mode (20 or 30 ms frames)", offsetof(ILBCEncContext, mode), AV_OPT_TYPE_INT, { .i64 = 20 }, 20, 30, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },

126 { NULL }

127 };

128

129 static const AVClass ilbc_enc_class = {

130 .class_name = "libilbc",

131 .item_name = av_default_item_name,

132 .option = ilbc_enc_options,

133 .version = LIBAVUTIL_VERSION_INT,

134 };

135

136 static av_cold int ilbc_encode_init(AVCodecContext *avctx)

137 {

138 ILBCEncContext *s = avctx->priv_data;

139 int mode;

140

141 if (avctx->sample_rate != 8000) {

142 av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");

143 return AVERROR(EINVAL);

144 }

145

146 if (avctx->channels != 1) {

147 av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");

148 return AVERROR(EINVAL);

149 }

150

151 if ((mode = get_mode(avctx)) > 0)

152 s->mode = mode;

153 else

154 s->mode = s->mode != 30 ? 20 : 30;

155 WebRtcIlbcfix_InitEncode(&s->encoder, s->mode);

156

157 avctx->block_align = s->encoder.no_of_bytes;

158 avctx->frame_size = s->encoder.blockl;

159

160 return 0;

161 }

162

163 static int ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,

164 const AVFrame *frame, int *got_packet_ptr)

165 {

166 ILBCEncContext *s = avctx->priv_data;

167 int ret;

168

169 if ((ret = ff_alloc_packet2(avctx, avpkt, 50)) < 0)

170 return ret;

171

172 WebRtcIlbcfix_EncodeImpl((uint16_t *) avpkt->data, (const int16_t *) frame->data[0], &s->encoder);

173

174 avpkt->size = s->encoder.no_of_bytes;

175 *got_packet_ptr = 1;

176 return 0;

177 }

178

179 static const AVCodecDefault ilbc_encode_defaults[] = {

180 { "b", "0" },

181 { NULL }

182 };

183

184 AVCodec ff_libilbc_encoder = {

185 .name = "libilbc",

186 .long_name = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),

187 .type = AVMEDIA_TYPE_AUDIO,

188 .id = AV_CODEC_ID_ILBC,

189 .priv_data_size = sizeof(ILBCEncContext),

190 .init = ilbc_encode_init,

191 .encode2 = ilbc_encode_frame,

192 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,

193 AV_SAMPLE_FMT_NONE },

194 .defaults = ilbc_encode_defaults,

195 .priv_class = &ilbc_enc_class,

196 };

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