/*
  * Interface to libshine for mp3 encoding
  * Copyright (c) 2012 Paul B Mahol
  *
  * 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 <shine/layer3.h>
 
 #include "libavutil/intreadwrite.h"
 #include "audio_frame_queue.h"
 #include "avcodec.h"
 #include "internal.h"
 #include "mpegaudio.h"
 #include "mpegaudiodecheader.h"
 
 #define BUFFER_SIZE (4096 * 20)
 
 typedef struct SHINEContext {
     shine_config_t  config;
     shine_t         shine;
     uint8_t         buffer[BUFFER_SIZE];
     int             buffer_index;
     AudioFrameQueue afq;
 } SHINEContext;
 
 static av_cold int libshine_encode_init(AVCodecContext *avctx)
 {
     SHINEContext *s = avctx->priv_data;
 
     if (avctx->channels <= 0 || avctx->channels > 2){
         av_log(avctx, AV_LOG_ERROR, "only mono or stereo is supported\n");
         return AVERROR(EINVAL);
     }
 
     shine_set_config_mpeg_defaults(&s->config.mpeg);
     if (avctx->bit_rate)
         s->config.mpeg.bitr = avctx->bit_rate / 1000;
     s->config.mpeg.mode = avctx->channels == 2 ? STEREO : MONO;
     s->config.wave.samplerate = avctx->sample_rate;
     s->config.wave.channels   = avctx->channels == 2 ? PCM_STEREO : PCM_MONO;

     if (shine_check_config(s->config.wave.samplerate, s->config.mpeg.bitr) < 0) {
         av_log(avctx, AV_LOG_ERROR, "invalid configuration\n");
         return AVERROR(EINVAL);
     }

     s->shine = shine_initialise(&s->config);
     if (!s->shine)
         return AVERROR(ENOMEM);

     avctx->frame_size = shine_samples_per_pass(s->shine);

     ff_af_queue_init(avctx, &s->afq);
     return 0;
 }
 
 static int libshine_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                                  const AVFrame *frame, int *got_packet_ptr)
 {
     SHINEContext *s = avctx->priv_data;
     MPADecodeHeader hdr;
     unsigned char *data;

     int written;

     int ret, len;
 
     if (frame)

         data = shine_encode_buffer(s->shine, (int16_t **)frame->data, &written);

     else
         data = shine_flush(s->shine, &written);
     if (written < 0)
         return -1;
     if (written > 0) {
         if (s->buffer_index + written > BUFFER_SIZE) {
             av_log(avctx, AV_LOG_ERROR, "internal buffer too small\n");
             return AVERROR_BUG;
         }
         memcpy(s->buffer + s->buffer_index, data, written);
         s->buffer_index += written;
     }
     if (frame) {
         if ((ret = ff_af_queue_add(&s->afq, frame)) < 0)
             return ret;
     }
 
     if (s->buffer_index < 4 || !s->afq.frame_count)
         return 0;
     if (avpriv_mpegaudio_decode_header(&hdr, AV_RB32(s->buffer))) {
         av_log(avctx, AV_LOG_ERROR, "free format output not supported\n");
         return -1;
     }
 
     len = hdr.frame_size;
     if (len <= s->buffer_index) {

         if ((ret = ff_alloc_packet2(avctx, avpkt, len, 0)))

             return ret;
         memcpy(avpkt->data, s->buffer, len);
         s->buffer_index -= len;
         memmove(s->buffer, s->buffer + len, s->buffer_index);
 
         ff_af_queue_remove(&s->afq, avctx->frame_size, &avpkt->pts,
                            &avpkt->duration);
 
         avpkt->size = len;
         *got_packet_ptr = 1;
     }
     return 0;
 }
 
 static av_cold int libshine_encode_close(AVCodecContext *avctx)
 {
     SHINEContext *s = avctx->priv_data;
 
     ff_af_queue_close(&s->afq);
     shine_close(s->shine);
     return 0;
 }
 
 static const int libshine_sample_rates[] = {
     44100, 48000, 32000, 0
 };
 
 AVCodec ff_libshine_encoder = {
     .name                  = "libshine",

     .long_name             = NULL_IF_CONFIG_SMALL("libshine MP3 (MPEG audio layer 3)"),

     .type                  = AVMEDIA_TYPE_AUDIO,

     .id                    = AV_CODEC_ID_MP3,

     .priv_data_size        = sizeof(SHINEContext),
     .init                  = libshine_encode_init,
     .encode2               = libshine_encode_frame,
     .close                 = libshine_encode_close,

     .capabilities          = AV_CODEC_CAP_DELAY,

     .sample_fmts           = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16P,
                                                             AV_SAMPLE_FMT_NONE },
     .supported_samplerates = libshine_sample_rates,
     .channel_layouts       = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
                                                   AV_CH_LAYOUT_STEREO,
                                                   0 },
 };