/*
  * iLBC decoder/encoder stub
  * Copyright (c) 2012 Martin Storsjo
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <ilbc.h>
 

 #include "libavutil/channel_layout.h"

 #include "libavutil/common.h"

 #include "libavutil/opt.h"

 #include "avcodec.h"

 #include "internal.h"
 
 static int get_mode(AVCodecContext *avctx)
 {
     if (avctx->block_align == 38)
         return 20;
     else if (avctx->block_align == 50)
         return 30;
     else if (avctx->bit_rate > 0)
         return avctx->bit_rate <= 14000 ? 30 : 20;
     else
         return -1;
 }
 
 typedef struct ILBCDecContext {
     const AVClass *class;
     iLBC_Dec_Inst_t decoder;
     int enhance;
 } ILBCDecContext;
 
 static const AVOption ilbc_dec_options[] = {

     { "enhance", "Enhance the decoded audio (adds delay)", offsetof(ILBCDecContext, enhance), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM },

     { NULL }
 };
 
 static const AVClass ilbc_dec_class = {

     .class_name = "libilbc",
     .item_name  = av_default_item_name,
     .option     = ilbc_dec_options,

     .version    = LIBAVUTIL_VERSION_INT,

 };
 
 static av_cold int ilbc_decode_init(AVCodecContext *avctx)
 {
     ILBCDecContext *s  = avctx->priv_data;
     int mode;
 
     if ((mode = get_mode(avctx)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "iLBC frame mode not indicated\n");
         return AVERROR(EINVAL);
     }
 
     WebRtcIlbcfix_InitDecode(&s->decoder, mode, s->enhance);
 

     avctx->channels       = 1;
     avctx->channel_layout = AV_CH_LAYOUT_MONO;
     avctx->sample_rate    = 8000;
     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;

 
     return 0;
 }
 
 static int ilbc_decode_frame(AVCodecContext *avctx, void *data,
                              int *got_frame_ptr, AVPacket *avpkt)
 {
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;
     ILBCDecContext *s  = avctx->priv_data;

     AVFrame *frame     = data;

     int ret;
 
     if (s->decoder.no_of_bytes > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "iLBC frame too short (%u, should be %u)\n",
                buf_size, s->decoder.no_of_bytes);
         return AVERROR_INVALIDDATA;
     }
 

     frame->nb_samples = s->decoder.blockl;

     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

         return ret;
 

     WebRtcIlbcfix_DecodeImpl((WebRtc_Word16*) frame->data[0],

                              (const WebRtc_UWord16*) buf, &s->decoder, 1);
 

     *got_frame_ptr = 1;

 
     return s->decoder.no_of_bytes;
 }
 
 AVCodec ff_libilbc_decoder = {
     .name           = "libilbc",

     .long_name      = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_ILBC,

     .priv_data_size = sizeof(ILBCDecContext),
     .init           = ilbc_decode_init,
     .decode         = ilbc_decode_frame,
     .capabilities   = CODEC_CAP_DR1,
     .priv_class     = &ilbc_dec_class,
 };
 
 typedef struct ILBCEncContext {
     const AVClass *class;
     iLBC_Enc_Inst_t encoder;
     int mode;
 } ILBCEncContext;
 
 static const AVOption ilbc_enc_options[] = {

     { "mode", "iLBC mode (20 or 30 ms frames)", offsetof(ILBCEncContext, mode), AV_OPT_TYPE_INT, { .i64 = 20 }, 20, 30, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },

     { NULL }
 };
 
 static const AVClass ilbc_enc_class = {

     .class_name = "libilbc",
     .item_name  = av_default_item_name,
     .option     = ilbc_enc_options,
     .version    = LIBAVUTIL_VERSION_INT,

 };
 
 static av_cold int ilbc_encode_init(AVCodecContext *avctx)
 {
     ILBCEncContext *s = avctx->priv_data;
     int mode;
 
     if (avctx->sample_rate != 8000) {
         av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
         return AVERROR(EINVAL);
     }
 
     if (avctx->channels != 1) {
         av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
         return AVERROR(EINVAL);
     }
 
     if ((mode = get_mode(avctx)) > 0)
         s->mode = mode;
     else
         s->mode = s->mode != 30 ? 20 : 30;
     WebRtcIlbcfix_InitEncode(&s->encoder, s->mode);
 
     avctx->block_align = s->encoder.no_of_bytes;
     avctx->frame_size  = s->encoder.blockl;
 
     return 0;
 }
 
 static int ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                              const AVFrame *frame, int *got_packet_ptr)
 {
     ILBCEncContext *s = avctx->priv_data;
     int ret;
 

     if ((ret = ff_alloc_packet2(avctx, avpkt, 50)) < 0)

         return ret;
 
     WebRtcIlbcfix_EncodeImpl((WebRtc_UWord16*) avpkt->data, (const WebRtc_Word16*) frame->data[0], &s->encoder);
 
     avpkt->size     = s->encoder.no_of_bytes;
     *got_packet_ptr = 1;
     return 0;
 }
 
 static const AVCodecDefault ilbc_encode_defaults[] = {
     { "b", "0" },
     { NULL }
 };
 
 AVCodec ff_libilbc_encoder = {
     .name           = "libilbc",

     .long_name      = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_ILBC,

     .priv_data_size = sizeof(ILBCEncContext),
     .init           = ilbc_encode_init,
     .encode2        = ilbc_encode_frame,
     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
                                                      AV_SAMPLE_FMT_NONE },
     .defaults       = ilbc_encode_defaults,
     .priv_class     = &ilbc_enc_class,
 };