/*
  * AMR Audio decoder stub
  * Copyright (c) 2003 the ffmpeg project
  *
  * 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 "avcodec.h"

 #include "libavutil/avstring.h"

 #include "libavutil/opt.h"

 
 static void amr_decode_fix_avctx(AVCodecContext *avctx)
 {
     const int is_amr_wb = 1 + (avctx->codec_id == CODEC_ID_AMR_WB);
 
     if (!avctx->sample_rate)
         avctx->sample_rate = 8000 * is_amr_wb;
 
     if (!avctx->channels)
         avctx->channels = 1;
 
     avctx->frame_size = 160 * is_amr_wb;

     avctx->sample_fmt = AV_SAMPLE_FMT_S16;

 }
 
 #if CONFIG_LIBOPENCORE_AMRNB
 
 #include <opencore-amrnb/interf_dec.h>
 #include <opencore-amrnb/interf_enc.h>
 
 /* Common code for fixed and float version*/
 typedef struct AMR_bitrates {
     int       rate;
     enum Mode mode;
 } AMR_bitrates;
 
 /* Match desired bitrate */

 static int get_bitrate_mode(int bitrate, void *log_ctx)

 {
     /* make the correspondance between bitrate and mode */

     static const AMR_bitrates rates[] = {
         { 4750, MR475 }, { 5150, MR515 }, {  5900, MR59  }, {  6700, MR67  },
         { 7400, MR74 },  { 7950, MR795 }, { 10200, MR102 }, { 12200, MR122 }
     };

     int i, best = -1, min_diff = 0;
     char log_buf[200];

     for (i = 0; i < 8; i++) {

         if (rates[i].rate == bitrate)
             return rates[i].mode;

         if (best < 0 || abs(rates[i].rate - bitrate) < min_diff) {
             best     = i;
             min_diff = abs(rates[i].rate - bitrate);
         }
     }
     /* no bitrate matching exactly, log a warning */
     snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");
     for (i = 0; i < 8; i++)
         av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i].rate    / 1000.f);
     av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best].rate / 1000.f);
     av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);
 
     return best;

 }
 
 typedef struct AMRContext {

     AVClass *av_class;

     AVFrame frame;

     void *dec_state;
     void *enc_state;

     int   enc_bitrate;

     int   enc_mode;

     int   enc_dtx;

 } AMRContext;
 

 static const AVOption options[] = {

     { "dtx", "Allow DTX (generate comfort noise)", offsetof(AMRContext, enc_dtx), AV_OPT_TYPE_INT, { 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },

     { NULL }
 };
 
 static const AVClass class = {
     "libopencore_amrnb", av_default_item_name, options, LIBAVUTIL_VERSION_INT
 };
 

 static av_cold int amr_nb_decode_init(AVCodecContext *avctx)
 {

     AMRContext *s  = avctx->priv_data;

     s->dec_state   = Decoder_Interface_init();
     if (!s->dec_state) {

         av_log(avctx, AV_LOG_ERROR, "Decoder_Interface_init error\n");

         return -1;
     }
 
     amr_decode_fix_avctx(avctx);
 
     if (avctx->channels > 1) {
         av_log(avctx, AV_LOG_ERROR, "amr_nb: multichannel decoding not supported\n");

         return AVERROR(ENOSYS);

     }
 

     avcodec_get_frame_defaults(&s->frame);
     avctx->coded_frame = &s->frame;
 

     return 0;
 }
 
 static av_cold int amr_nb_decode_close(AVCodecContext *avctx)
 {
     AMRContext *s = avctx->priv_data;
 

     Decoder_Interface_exit(s->dec_state);

     return 0;
 }
 
 static int amr_nb_decode_frame(AVCodecContext *avctx, void *data,

                                int *got_frame_ptr, AVPacket *avpkt)

 {
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;

     AMRContext *s      = avctx->priv_data;

     static const uint8_t block_size[16] = { 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 };
     enum Mode dec_mode;

     int packet_size, ret;

     av_dlog(avctx, "amr_decode_frame buf=%p buf_size=%d frame_count=%d!!\n",

             buf, buf_size, avctx->frame_number);

     /* get output buffer */
     s->frame.nb_samples = 160;
     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;

     }

     dec_mode    = (buf[0] >> 3) & 0x000F;

     packet_size = block_size[dec_mode] + 1;
 
     if (packet_size > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "amr frame too short (%u, should be %u)\n",
                buf_size, packet_size);

         return AVERROR_INVALIDDATA;

     }
 

     av_dlog(avctx, "packet_size=%d buf= 0x%X %X %X %X\n",
               packet_size, buf[0], buf[1], buf[2], buf[3]);

     /* call decoder */

     Decoder_Interface_Decode(s->dec_state, buf, (short *)s->frame.data[0], 0);
 
     *got_frame_ptr   = 1;
     *(AVFrame *)data = s->frame;

 
     return packet_size;
 }
 

 AVCodec ff_libopencore_amrnb_decoder = {

     .name           = "libopencore_amrnb",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_AMR_NB,
     .priv_data_size = sizeof(AMRContext),
     .init           = amr_nb_decode_init,
     .close          = amr_nb_decode_close,
     .decode         = amr_nb_decode_frame,

     .capabilities   = CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("OpenCORE Adaptive Multi-Rate (AMR) Narrow-Band"),
 };
 
 static av_cold int amr_nb_encode_init(AVCodecContext *avctx)
 {
     AMRContext *s = avctx->priv_data;
 
     if (avctx->sample_rate != 8000) {
         av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");

         return AVERROR(ENOSYS);

     }
 
     if (avctx->channels != 1) {
         av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");

         return AVERROR(ENOSYS);

     }
 
     avctx->frame_size  = 160;
     avctx->coded_frame = avcodec_alloc_frame();
 

     s->enc_state = Encoder_Interface_init(s->enc_dtx);

     if (!s->enc_state) {

         av_log(avctx, AV_LOG_ERROR, "Encoder_Interface_init error\n");
         return -1;
     }
 

     s->enc_mode    = get_bitrate_mode(avctx->bit_rate, avctx);
     s->enc_bitrate = avctx->bit_rate;

 
     return 0;
 }
 
 static av_cold int amr_nb_encode_close(AVCodecContext *avctx)
 {
     AMRContext *s = avctx->priv_data;
 

     Encoder_Interface_exit(s->enc_state);

     av_freep(&avctx->coded_frame);
     return 0;
 }
 
 static int amr_nb_encode_frame(AVCodecContext *avctx,
                                unsigned char *frame/*out*/,
                                int buf_size, void *data/*in*/)
 {
     AMRContext *s = avctx->priv_data;
     int written;
 

     if (s->enc_bitrate != avctx->bit_rate) {
         s->enc_mode    = get_bitrate_mode(avctx->bit_rate, avctx);
         s->enc_bitrate = avctx->bit_rate;

     }
 

     written = Encoder_Interface_Encode(s->enc_state, s->enc_mode, data,

                                        frame, 0);

     av_dlog(avctx, "amr_nb_encode_frame encoded %u bytes, bitrate %u, first byte was %#02x\n",

             written, s->enc_mode, frame[0]);

 
     return written;
 }
 

 AVCodec ff_libopencore_amrnb_encoder = {

     .name           = "libopencore_amrnb",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_AMR_NB,
     .priv_data_size = sizeof(AMRContext),
     .init           = amr_nb_encode_init,
     .encode         = amr_nb_encode_frame,
     .close          = amr_nb_encode_close,

     .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},

     .long_name = NULL_IF_CONFIG_SMALL("OpenCORE Adaptive Multi-Rate (AMR) Narrow-Band"),

     .priv_class = &class,

 };
 
 #endif
 
 /* -----------AMR wideband ------------*/
 #if CONFIG_LIBOPENCORE_AMRWB
 
 #include <opencore-amrwb/dec_if.h>
 #include <opencore-amrwb/if_rom.h>
 
 typedef struct AMRWBContext {

     AVFrame frame;

     void  *state;
 } AMRWBContext;
 
 static av_cold int amr_wb_decode_init(AVCodecContext *avctx)
 {
     AMRWBContext *s = avctx->priv_data;
 

     s->state        = D_IF_init();

 
     amr_decode_fix_avctx(avctx);
 
     if (avctx->channels > 1) {
         av_log(avctx, AV_LOG_ERROR, "amr_wb: multichannel decoding not supported\n");

         return AVERROR(ENOSYS);

     }
 

     avcodec_get_frame_defaults(&s->frame);
     avctx->coded_frame = &s->frame;
 

     return 0;
 }
 
 static int amr_wb_decode_frame(AVCodecContext *avctx, void *data,

                                int *got_frame_ptr, AVPacket *avpkt)

 {
     const uint8_t *buf = avpkt->data;
     int buf_size       = avpkt->size;

     AMRWBContext *s    = avctx->priv_data;

     int mode, ret;
     int packet_size;

     static const uint8_t block_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};
 

     /* get output buffer */
     s->frame.nb_samples = 320;
     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;

     }

     mode        = (buf[0] >> 3) & 0x000F;

     packet_size = block_size[mode];
 
     if (packet_size > buf_size) {
         av_log(avctx, AV_LOG_ERROR, "amr frame too short (%u, should be %u)\n",
                buf_size, packet_size + 1);

         return AVERROR_INVALIDDATA;

     }
 

     D_IF_decode(s->state, buf, (short *)s->frame.data[0], _good_frame);
 
     *got_frame_ptr   = 1;
     *(AVFrame *)data = s->frame;
 

     return packet_size;
 }
 
 static int amr_wb_decode_close(AVCodecContext *avctx)
 {
     AMRWBContext *s = avctx->priv_data;
 
     D_IF_exit(s->state);
     return 0;
 }
 

 AVCodec ff_libopencore_amrwb_decoder = {

     .name           = "libopencore_amrwb",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_AMR_WB,
     .priv_data_size = sizeof(AMRWBContext),
     .init           = amr_wb_decode_init,
     .close          = amr_wb_decode_close,
     .decode         = amr_wb_decode_frame,

     .capabilities   = CODEC_CAP_DR1,

     .long_name = NULL_IF_CONFIG_SMALL("OpenCORE Adaptive Multi-Rate (AMR) Wide-Band"),
 };
 
 #endif /* CONFIG_LIBOPENCORE_AMRWB */