FFmpeg: libavcodec/libvo-amrwbenc.c Source File

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libavcodec

libvo-amrwbenc.c

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1 /*

2 * AMR Audio 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 <vo-amrwbenc/enc_if.h>

23 #include <stdio.h>

24 #include <stdlib.h>

26 #include "libavutil/avstring.h"

27 #include "libavutil/internal.h"

28 #include "libavutil/mem.h"

29 #include "libavutil/opt.h"

30 #include "avcodec.h"

31 #include "internal.h"

33 #define MAX_PACKET_SIZE (1 + (477 + 7) / 8)

35 typedef struct AMRWBContext {

36 AVClass *av_class;

37 void *state;

38 int mode;

39 int last_bitrate;

40 int allow_dtx;

41 } AMRWBContext;

43 static const AVOption options[] = {

44 { "dtx", "Allow DTX (generate comfort noise)", offsetof(AMRWBContext, allow_dtx), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },

45 { NULL }

46 };

48 static const AVClass class = {

49 "libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT

50 };

52 static int get_wb_bitrate_mode(int bitrate, void *log_ctx)

53 {

54 /* make the correspondance between bitrate and mode */

55 static const int rates[] = { 6600, 8850, 12650, 14250, 15850, 18250,

56 19850, 23050, 23850 };

57 int i, best = -1, min_diff = 0;

58 char log_buf[200];

60 for (i = 0; i < 9; i++) {

61 if (rates[i] == bitrate)

62 return i;

63 if (best < 0 || abs(rates[i] - bitrate) < min_diff) {

64 best = i;

65 min_diff = abs(rates[i] - bitrate);

66 }

67 }

68 /* no bitrate matching exactly, log a warning */

69 snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");

70 for (i = 0; i < 9; i++)

71 av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i] / 1000.f);

72 av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f);

73 av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);

75 return best;

76 }

78 static av_cold int amr_wb_encode_init(AVCodecContext *avctx)

79 {

80 AMRWBContext *s = avctx->priv_data;

82 if (avctx->sample_rate != 16000 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {

83 av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");

84 return AVERROR(ENOSYS);

85 }

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

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

89 return AVERROR(ENOSYS);

90 }

92 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);

93 s->last_bitrate = avctx->bit_rate;

95 avctx->frame_size = 320;

96 avctx->delay = 80;

97 #if FF_API_OLD_ENCODE_AUDIO

98 avctx->coded_frame = avcodec_alloc_frame();

99 if (!avctx->coded_frame)

100 return AVERROR(ENOMEM);

101 #endif

102

103 s->state = E_IF_init();

104

105 return 0;

106 }

107

108 static int amr_wb_encode_close(AVCodecContext *avctx)

109 {

110 AMRWBContext *s = avctx->priv_data;

111

112 E_IF_exit(s->state);

113 av_freep(&avctx->coded_frame);

114 return 0;

115 }

116

117 static int amr_wb_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,

118 const AVFrame *frame, int *got_packet_ptr)

119 {

120 AMRWBContext *s = avctx->priv_data;

121 const int16_t *samples = (const int16_t *)frame->data[0];

122 int size, ret;

123

124 if ((ret = ff_alloc_packet2(avctx, avpkt, MAX_PACKET_SIZE)))

125 return ret;

126

127 if (s->last_bitrate != avctx->bit_rate) {

128 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);

129 s->last_bitrate = avctx->bit_rate;

130 }

131 size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);

132 if (size <= 0 || size > MAX_PACKET_SIZE) {

133 av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");

134 return AVERROR(EINVAL);

135 }

136

137 if (frame->pts != AV_NOPTS_VALUE)

138 avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->delay);

139

140 avpkt->size = size;

141 *got_packet_ptr = 1;

142 return 0;

143 }

144

145 AVCodec ff_libvo_amrwbenc_encoder = {

146 .name = "libvo_amrwbenc",

147 .type = AVMEDIA_TYPE_AUDIO,

148 .id = AV_CODEC_ID_AMR_WB,

149 .priv_data_size = sizeof(AMRWBContext),

150 .init = amr_wb_encode_init,

151 .encode2 = amr_wb_encode_frame,

152 .close = amr_wb_encode_close,

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

154 AV_SAMPLE_FMT_NONE },

155 .long_name = NULL_IF_CONFIG_SMALL("Android VisualOn AMR-WB "

156 "(Adaptive Multi-Rate Wide-Band)"),

157 .priv_class = &class,

158 };

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