1/*
2 * AMR Audio encoder stub
3 * Copyright (c) 2003 the ffmpeg project
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 <vo-amrwbenc/enc_if.h>
23#include <stdio.h>
24#include <stdlib.h>
25
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"
32
33#define MAX_PACKET_SIZE  (1 + (477 + 7) / 8)
34
35typedef struct AMRWBContext {
36    AVClass *av_class;
37    void  *state;
38    int    mode;
39    int    last_bitrate;
40    int    allow_dtx;
41} AMRWBContext;
42
43static 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};
47
48static const AVClass amrwb_class = {
49    "libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT
50};
51
52static 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];
59
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);
74
75    return best;
76}
77
78static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
79{
80    AMRWBContext *s = avctx->priv_data;
81
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    }
86
87    if (avctx->channels != 1) {
88        av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
89        return AVERROR(ENOSYS);
90    }
91
92    s->mode            = get_wb_bitrate_mode(avctx->bit_rate, avctx);
93    s->last_bitrate    = avctx->bit_rate;
94
95    avctx->frame_size  = 320;
96    avctx->delay       =  80;
97
98    s->state     = E_IF_init();
99
100    return 0;
101}
102
103static int amr_wb_encode_close(AVCodecContext *avctx)
104{
105    AMRWBContext *s = avctx->priv_data;
106
107    E_IF_exit(s->state);
108    return 0;
109}
110
111static int amr_wb_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
112                               const AVFrame *frame, int *got_packet_ptr)
113{
114    AMRWBContext *s = avctx->priv_data;
115    const int16_t *samples = (const int16_t *)frame->data[0];
116    int size, ret;
117
118    if ((ret = ff_alloc_packet2(avctx, avpkt, MAX_PACKET_SIZE)) < 0)
119        return ret;
120
121    if (s->last_bitrate != avctx->bit_rate) {
122        s->mode         = get_wb_bitrate_mode(avctx->bit_rate, avctx);
123        s->last_bitrate = avctx->bit_rate;
124    }
125    size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);
126    if (size <= 0 || size > MAX_PACKET_SIZE) {
127        av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");
128        return AVERROR(EINVAL);
129    }
130
131    if (frame->pts != AV_NOPTS_VALUE)
132        avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->delay);
133
134    avpkt->size = size;
135    *got_packet_ptr = 1;
136    return 0;
137}
138
139AVCodec ff_libvo_amrwbenc_encoder = {
140    .name           = "libvo_amrwbenc",
141    .long_name      = NULL_IF_CONFIG_SMALL("Android VisualOn AMR-WB "
142                                           "(Adaptive Multi-Rate Wide-Band)"),
143    .type           = AVMEDIA_TYPE_AUDIO,
144    .id             = AV_CODEC_ID_AMR_WB,
145    .priv_data_size = sizeof(AMRWBContext),
146    .init           = amr_wb_encode_init,
147    .encode2        = amr_wb_encode_frame,
148    .close          = amr_wb_encode_close,
149    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
150                                                     AV_SAMPLE_FMT_NONE },
151    .priv_class     = &amrwb_class,
152};
153