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     "libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT
  50 };
  51
  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];
  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
  78 static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
  79 {
  80     AMRWBContext *s = avctx->priv_data;
  81
  82     if (avctx->sample_rate != 16000) {
  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 #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_packet(avpkt, MAX_PACKET_SIZE))) {
 125         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
 126         return ret;
 127     }
 128
 129     if (s->last_bitrate != avctx->bit_rate) {
 130         s->mode         = get_wb_bitrate_mode(avctx->bit_rate, avctx);
 131         s->last_bitrate = avctx->bit_rate;
 132     }
 133     size = E_IF_encode(s->state, s->mode, samples, avpkt->data, s->allow_dtx);
 134     if (size <= 0 || size > MAX_PACKET_SIZE) {
 135         av_log(avctx, AV_LOG_ERROR, "Error encoding frame\n");
 136         return AVERROR(EINVAL);
 137     }
 138
 139     if (frame->pts != AV_NOPTS_VALUE)
 140         avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->delay);
 141
 142     avpkt->size = size;
 143     *got_packet_ptr = 1;
 144     return 0;
 145 }
 146
 147 AVCodec ff_libvo_amrwbenc_encoder = {
 148     .name           = "libvo_amrwbenc",
 149     .type           = AVMEDIA_TYPE_AUDIO,
 150     .id             = AV_CODEC_ID_AMR_WB,
 151     .priv_data_size = sizeof(AMRWBContext),
 152     .init           = amr_wb_encode_init,
 153     .encode2        = amr_wb_encode_frame,
 154     .close          = amr_wb_encode_close,
 155     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
 156                                                      AV_SAMPLE_FMT_NONE },
 157     .long_name      = NULL_IF_CONFIG_SMALL("Android VisualOn AMR-WB "
 158                                            "(Adaptive Multi-Rate Wide-Band)"),
 159     .priv_class     = &class,
 160 };