libavcodec/libvo-amrwbenc.c

   1 /*
   2  * AMR Audio encoder stub
   3  * Copyright (c) 2003 The FFmpeg project
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  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 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) {
  86         av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
  87         return AVERROR(ENOSYS);
  88     }
  89
  90     if (avctx->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(avpkt, MAX_PACKET_SIZE))) {
 122         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
 123         return ret;
 124     }
 125
 126     if (s->last_bitrate != avctx->bit_rate) {
 127         s->mode         = get_wb_bitrate_mode(avctx->bit_rate, avctx);
 128         s->last_bitrate = avctx->bit_rate;
 129     }
 130     size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);
 131     if (size <= 0 || size > MAX_PACKET_SIZE) {
 132         av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");
 133         return AVERROR(EINVAL);
 134     }
 135
 136     if (frame->pts != AV_NOPTS_VALUE)
 137         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
 138
 139     avpkt->size = size;
 140     *got_packet_ptr = 1;
 141     return 0;
 142 }
 143
 144 AVCodec ff_libvo_amrwbenc_encoder = {
 145     .name           = "libvo_amrwbenc",
 146     .long_name      = NULL_IF_CONFIG_SMALL("Android VisualOn AMR-WB "
 147                                            "(Adaptive Multi-Rate Wide-Band)"),
 148     .type           = AVMEDIA_TYPE_AUDIO,
 149     .id             = AV_CODEC_ID_AMR_WB,
 150     .priv_data_size = sizeof(AMRWBContext),
 151     .init           = amr_wb_encode_init,
 152     .encode2        = amr_wb_encode_frame,
 153     .close          = amr_wb_encode_close,
 154     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
 155                                                      AV_SAMPLE_FMT_NONE },
 156     .priv_class     = &class,
 157     .wrapper_name   = "libvo_amrwbenc",
 158 };