/*
  * Interface to libfaac for aac encoding
  * Copyright (c) 2002 Gildas Bazin <gbazin@netcourrier.com>
  *

  * 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

  */

 /**

  * @file

  * Interface to libfaac for aac encoding.
  */
 
 #include <faac.h>
 

 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"

 #include "avcodec.h"
 #include "audio_frame_queue.h"
 #include "internal.h"
 
 
 /* libfaac has an encoder delay of 1024 samples */
 #define FAAC_DELAY_SAMPLES 1024
 

 typedef struct FaacAudioContext {
     faacEncHandle faac_handle;

     AudioFrameQueue afq;

 } FaacAudioContext;
 

 static av_cold int Faac_encode_close(AVCodecContext *avctx)
 {
     FaacAudioContext *s = avctx->priv_data;
 
     av_freep(&avctx->extradata);

     ff_af_queue_close(&s->afq);

 
     if (s->faac_handle)
         faacEncClose(s->faac_handle);

     return 0;
 }
 

 static const int channel_maps[][6] = {
     { 2, 0, 1 },          //< C L R
     { 2, 0, 1, 3 },       //< C L R Cs
     { 2, 0, 1, 3, 4 },    //< C L R Ls Rs
     { 2, 0, 1, 4, 5, 3 }, //< C L R Ls Rs LFE
 };
 

 static av_cold int Faac_encode_init(AVCodecContext *avctx)

 {
     FaacAudioContext *s = avctx->priv_data;
     faacEncConfigurationPtr faac_cfg;
     unsigned long samples_input, max_bytes_output;

     int ret;

 
     /* number of channels */

     if (avctx->channels < 1 || avctx->channels > 6) {
         av_log(avctx, AV_LOG_ERROR, "encoding %d channel(s) is not allowed\n", avctx->channels);

         ret = AVERROR(EINVAL);
         goto error;

     }

 
     s->faac_handle = faacEncOpen(avctx->sample_rate,
                                  avctx->channels,
                                  &samples_input, &max_bytes_output);

     if (!s->faac_handle) {
         av_log(avctx, AV_LOG_ERROR, "error in faacEncOpen()\n");
         ret = AVERROR_UNKNOWN;
         goto error;
     }

 
     /* check faac version */
     faac_cfg = faacEncGetCurrentConfiguration(s->faac_handle);
     if (faac_cfg->version != FAAC_CFG_VERSION) {

         av_log(avctx, AV_LOG_ERROR, "wrong libfaac version (compiled for: %d, using %d)\n", FAAC_CFG_VERSION, faac_cfg->version);

         ret = AVERROR(EINVAL);
         goto error;

     }
 
     /* put the options in the configuration struct */

     switch(avctx->profile) {
         case FF_PROFILE_AAC_MAIN:
             faac_cfg->aacObjectType = MAIN;
             break;
         case FF_PROFILE_UNKNOWN:
         case FF_PROFILE_AAC_LOW:
             faac_cfg->aacObjectType = LOW;
             break;
         case FF_PROFILE_AAC_SSR:
             faac_cfg->aacObjectType = SSR;
             break;
         case FF_PROFILE_AAC_LTP:
             faac_cfg->aacObjectType = LTP;
             break;
         default:
             av_log(avctx, AV_LOG_ERROR, "invalid AAC profile\n");

             ret = AVERROR(EINVAL);
             goto error;

     }

     faac_cfg->mpegVersion = MPEG4;
     faac_cfg->useTns = 0;
     faac_cfg->allowMidside = 1;

     faac_cfg->bitRate = avctx->bit_rate / avctx->channels;

     faac_cfg->bandWidth = avctx->cutoff;

     if(avctx->flags & CODEC_FLAG_QSCALE) {
         faac_cfg->bitRate = 0;
         faac_cfg->quantqual = avctx->global_quality / FF_QP2LAMBDA;
     }

     faac_cfg->outputFormat = 1;

     faac_cfg->inputFormat = FAAC_INPUT_16BIT;

     if (avctx->channels > 2)
         memcpy(faac_cfg->channel_map, channel_maps[avctx->channels-3],
                avctx->channels * sizeof(int));

 
     avctx->frame_size = samples_input / avctx->channels;
 
     /* Set decoder specific info */
     avctx->extradata_size = 0;
     if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER) {
 

         unsigned char *buffer = NULL;

         unsigned long decoder_specific_info_size;
 
         if (!faacEncGetDecoderSpecificInfo(s->faac_handle, &buffer,
                                            &decoder_specific_info_size)) {

             avctx->extradata = av_malloc(decoder_specific_info_size + FF_INPUT_BUFFER_PADDING_SIZE);

             if (!avctx->extradata) {
                 ret = AVERROR(ENOMEM);
                 goto error;
             }

             avctx->extradata_size = decoder_specific_info_size;

             memcpy(avctx->extradata, buffer, avctx->extradata_size);

             faac_cfg->outputFormat = 0;

         }

         free(buffer);

     }
 

     if (!faacEncSetConfiguration(s->faac_handle, faac_cfg)) {

         int i;
         for (i = avctx->bit_rate/1000; i ; i--) {
             faac_cfg->bitRate = 1000*i / avctx->channels;
             if (faacEncSetConfiguration(s->faac_handle, faac_cfg))
                 break;
         }
         if (!i) {
             av_log(avctx, AV_LOG_ERROR, "libfaac doesn't support this output format!\n");
             ret = AVERROR(EINVAL);
             goto error;
         } else {
             avctx->bit_rate = 1000*i;
             av_log(avctx, AV_LOG_WARNING, "libfaac doesn't support the specified bitrate, using %dkbit/s instead\n", i);
         }

     }
 

     avctx->delay = FAAC_DELAY_SAMPLES;
     ff_af_queue_init(avctx, &s->afq);
 

     return 0;

 error:
     Faac_encode_close(avctx);
     return ret;

 }
 

 static int Faac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                              const AVFrame *frame, int *got_packet_ptr)

 {
     FaacAudioContext *s = avctx->priv_data;

     int bytes_written, ret;
     int num_samples  = frame ? frame->nb_samples : 0;
     void *samples    = frame ? frame->data[0]    : NULL;

     if ((ret = ff_alloc_packet2(avctx, avpkt, (7 + 768) * avctx->channels)) < 0)

         return ret;
 
     bytes_written = faacEncEncode(s->faac_handle, samples,

                                   num_samples * avctx->channels,

                                   avpkt->data, avpkt->size);
     if (bytes_written < 0) {
         av_log(avctx, AV_LOG_ERROR, "faacEncEncode() error\n");
         return bytes_written;
     }
 
     /* add current frame to the queue */
     if (frame) {

         if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)

             return ret;
     }

     if (!bytes_written)
         return 0;
 
     /* Get the next frame pts/duration */
     ff_af_queue_remove(&s->afq, avctx->frame_size, &avpkt->pts,
                        &avpkt->duration);
 
     avpkt->size = bytes_written;
     *got_packet_ptr = 1;
     return 0;

 }
 

 static const AVProfile profiles[] = {
     { FF_PROFILE_AAC_MAIN, "Main" },
     { FF_PROFILE_AAC_LOW,  "LC"   },
     { FF_PROFILE_AAC_SSR,  "SSR"  },
     { FF_PROFILE_AAC_LTP,  "LTP"  },
     { FF_PROFILE_UNKNOWN },
 };
 

 static const uint64_t faac_channel_layouts[] = {
     AV_CH_LAYOUT_MONO,
     AV_CH_LAYOUT_STEREO,
     AV_CH_LAYOUT_SURROUND,
     AV_CH_LAYOUT_4POINT0,
     AV_CH_LAYOUT_5POINT0_BACK,
     AV_CH_LAYOUT_5POINT1_BACK,
     0
 };
 

 AVCodec ff_libfaac_encoder = {

     .name           = "libfaac",

     .long_name      = NULL_IF_CONFIG_SMALL("libfaac AAC (Advanced Audio Coding)"),

     .type           = AVMEDIA_TYPE_AUDIO,

     .id             = AV_CODEC_ID_AAC,

     .priv_data_size = sizeof(FaacAudioContext),
     .init           = Faac_encode_init,

     .encode2        = Faac_encode_frame,

     .close          = Faac_encode_close,

     .capabilities   = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY,
     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
                                                      AV_SAMPLE_FMT_NONE },
     .profiles       = NULL_IF_CONFIG_SMALL(profiles),

     .channel_layouts = faac_channel_layouts,

 };