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/opt.h"
29#include "avcodec.h"
30#include "codec_internal.h"
31#include "encode.h"
32#include "internal.h"
33
34#define MAX_PACKET_SIZE  (1 + (477 + 7) / 8)
35
36typedef struct AMRWBContext {
37    AVClass *av_class;
38    void  *state;
39    int    mode;
40    int    last_bitrate;
41    int    allow_dtx;
42} AMRWBContext;
43
44static const AVOption options[] = {
45    { "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 },
46    { NULL }
47};
48
49static const AVClass amrwb_class = {
50    .class_name = "libvo_amrwbenc",
51    .item_name  = av_default_item_name,
52    .option     = options,
53    .version    = LIBAVUTIL_VERSION_INT,
54};
55
56static int get_wb_bitrate_mode(int bitrate, void *log_ctx)
57{
58    /* make the correspondence between bitrate and mode */
59    static const int rates[] = {  6600,  8850, 12650, 14250, 15850, 18250,
60                                 19850, 23050, 23850 };
61    int i, best = -1, min_diff = 0;
62    char log_buf[200];
63
64    for (i = 0; i < 9; i++) {
65        if (rates[i] == bitrate)
66            return i;
67        if (best < 0 || abs(rates[i] - bitrate) < min_diff) {
68            best     = i;
69            min_diff = abs(rates[i] - bitrate);
70        }
71    }
72    /* no bitrate matching exactly, log a warning */
73    snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");
74    for (i = 0; i < 9; i++)
75        av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i]    / 1000.f);
76    av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f);
77    av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);
78
79    return best;
80}
81
82static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
83{
84    AMRWBContext *s = avctx->priv_data;
85
86    if (avctx->sample_rate != 16000 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
87        av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
88        return AVERROR(ENOSYS);
89    }
90
91    if (avctx->ch_layout.nb_channels != 1) {
92        av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
93        return AVERROR(ENOSYS);
94    }
95
96    s->mode            = get_wb_bitrate_mode(avctx->bit_rate, avctx);
97    s->last_bitrate    = avctx->bit_rate;
98
99    avctx->frame_size  = 320;
100    avctx->initial_padding =  80;
101
102    s->state     = E_IF_init();
103
104    return 0;
105}
106
107static int amr_wb_encode_close(AVCodecContext *avctx)
108{
109    AMRWBContext *s = avctx->priv_data;
110
111    E_IF_exit(s->state);
112    return 0;
113}
114
115static int amr_wb_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
116                               const AVFrame *frame, int *got_packet_ptr)
117{
118    AMRWBContext *s = avctx->priv_data;
119    const int16_t *samples = (const int16_t *)frame->data[0];
120    int size, ret;
121
122    if ((ret = ff_alloc_packet(avctx, avpkt, MAX_PACKET_SIZE)) < 0)
123        return ret;
124
125    if (s->last_bitrate != avctx->bit_rate) {
126        s->mode         = get_wb_bitrate_mode(avctx->bit_rate, avctx);
127        s->last_bitrate = avctx->bit_rate;
128    }
129    size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);
130    if (size <= 0 || size > MAX_PACKET_SIZE) {
131        av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");
132        return AVERROR(EINVAL);
133    }
134
135    if (frame->pts != AV_NOPTS_VALUE)
136        avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
137
138    avpkt->size = size;
139    *got_packet_ptr = 1;
140    return 0;
141}
142
143const FFCodec ff_libvo_amrwbenc_encoder = {
144    .p.name         = "libvo_amrwbenc",
145    .p.long_name    = NULL_IF_CONFIG_SMALL("Android VisualOn AMR-WB "
146                                           "(Adaptive Multi-Rate Wide-Band)"),
147    .p.type         = AVMEDIA_TYPE_AUDIO,
148    .p.id           = AV_CODEC_ID_AMR_WB,
149    .p.priv_class   = &amrwb_class,
150    .p.wrapper_name = "libvo_amrwbenc",
151    .priv_data_size = sizeof(AMRWBContext),
152    .init           = amr_wb_encode_init,
153    FF_CODEC_ENCODE_CB(amr_wb_encode_frame),
154    .close          = amr_wb_encode_close,
155    .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
156                                                     AV_SAMPLE_FMT_NONE },
157};
158