libavcodec/libvo-amrwbenc.c

   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
  33 #define MAX_PACKET_SIZE  (1 + (477 + 7) / 8)
  34
  35 typedef struct AMRWBContext {
  36     AVClass *av_class;
  37     void  *state;
  38     int    mode;
  39     int    last_bitrate;
  40     int    allow_dtx;
  41 } AMRWBContext;
  42
  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 };
  47
  48 static const AVClass amrwb_class = {
  49     .class_name = "libvo_amrwbenc",
  50     .item_name  = av_default_item_name,
  51     .option     = options,
  52     .version    = LIBAVUTIL_VERSION_INT,
  53 };
  54
  55 static int get_wb_bitrate_mode(int bitrate, void *log_ctx)
  56 {
  57     /* make the correspondence between bitrate and mode */
  58     static const int rates[] = {  6600,  8850, 12650, 14250, 15850, 18250,
  59                                  19850, 23050, 23850 };
  60     int i, best = -1, min_diff = 0;
  61     char log_buf[200];
  62
  63     for (i = 0; i < 9; i++) {
  64         if (rates[i] == bitrate)
  65             return i;
  66         if (best < 0 || abs(rates[i] - bitrate) < min_diff) {
  67             best     = i;
  68             min_diff = abs(rates[i] - bitrate);
  69         }
  70     }
  71     /* no bitrate matching exactly, log a warning */
  72     snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");
  73     for (i = 0; i < 9; i++)
  74         av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i]    / 1000.f);
  75     av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f);
  76     av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);
  77
  78     return best;
  79 }
  80
  81 static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
  82 {
  83     AMRWBContext *s = avctx->priv_data;
  84
  85     if (avctx->sample_rate != 16000 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
  86         av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
  87         return AVERROR(ENOSYS);
  88     }
  89
  90     if (avctx->ch_layout.nb_channels != 1) {
  91         av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
  92         return AVERROR(ENOSYS);
  93     }
  94
  95     s->mode            = get_wb_bitrate_mode(avctx->bit_rate, avctx);
  96     s->last_bitrate    = avctx->bit_rate;
  97
  98     avctx->frame_size  = 320;
  99     avctx->initial_padding =  80;
 100
 101     s->state     = E_IF_init();
 102
 103     return 0;
 104 }
 105
 106 static int amr_wb_encode_close(AVCodecContext *avctx)
 107 {
 108     AMRWBContext *s = avctx->priv_data;
 109
 110     E_IF_exit(s->state);
 111     return 0;
 112 }
 113
 114 static int amr_wb_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 115                                const AVFrame *frame, int *got_packet_ptr)
 116 {
 117     AMRWBContext *s = avctx->priv_data;
 118     const int16_t *samples = (const int16_t *)frame->data[0];
 119     int size, ret;
 120
 121     if ((ret = ff_alloc_packet(avctx, avpkt, MAX_PACKET_SIZE)) < 0)
 122         return ret;
 123
 124     if (s->last_bitrate != avctx->bit_rate) {
 125         s->mode         = get_wb_bitrate_mode(avctx->bit_rate, avctx);
 126         s->last_bitrate = avctx->bit_rate;
 127     }
 128     size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);
 129     if (size <= 0 || size > MAX_PACKET_SIZE) {
 130         av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");
 131         return AVERROR(EINVAL);
 132     }
 133
 134     if (frame->pts != AV_NOPTS_VALUE)
 135         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
 136
 137     avpkt->size = size;
 138     *got_packet_ptr = 1;
 139     return 0;
 140 }
 141
 142 const FFCodec ff_libvo_amrwbenc_encoder = {
 143     .p.name         = "libvo_amrwbenc",
 144     CODEC_LONG_NAME("Android VisualOn AMR-WB (Adaptive Multi-Rate Wide-Band)"),
 145     .p.type         = AVMEDIA_TYPE_AUDIO,
 146     .p.id           = AV_CODEC_ID_AMR_WB,
 147     .p.capabilities = AV_CODEC_CAP_DR1 |
 148                       AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
 149     .p.priv_class   = &amrwb_class,
 150     .p.wrapper_name = "libvo_amrwbenc",
 151     .caps_internal  = FF_CODEC_CAP_NOT_INIT_THREADSAFE,
 152     .priv_data_size = sizeof(AMRWBContext),
 153     .init           = amr_wb_encode_init,
 154     FF_CODEC_ENCODE_CB(amr_wb_encode_frame),
 155     .close          = amr_wb_encode_close,
 156     .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
 157                                                      AV_SAMPLE_FMT_NONE },
 158 };