/*
  * Interface to libtwolame for mp2 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
  */
 
 /**
  * @file
  * Interface to libtwolame for mp2 encoding.
  */
 
 #include <twolame.h>
 
 #include "libavutil/opt.h"
 #include "avcodec.h"
 #include "internal.h"
 #include "mpegaudio.h"
 
 typedef struct TWOLAMEContext {
     AVClass  *class;
     int      mode;
     int      psymodel;
     int      energy;
     int      error_protection;
     int      copyright;
     int      original;
 
     twolame_options *glopts;
     int64_t  next_pts;
 } TWOLAMEContext;
 
 static av_cold int twolame_encode_close(AVCodecContext *avctx)
 {
     TWOLAMEContext *s = avctx->priv_data;
     twolame_close(&s->glopts);
     return 0;
 }
 
 static av_cold int twolame_encode_init(AVCodecContext *avctx)
 {
     TWOLAMEContext *s = avctx->priv_data;
     int ret;
 
     avctx->frame_size = TWOLAME_SAMPLES_PER_FRAME;
 
     s->glopts = twolame_init();
     if (!s->glopts)
         return AVERROR(ENOMEM);
 
     twolame_set_verbosity(s->glopts, 0);
     twolame_set_mode(s->glopts, s->mode);
     twolame_set_psymodel(s->glopts, s->psymodel);
     twolame_set_energy_levels(s->glopts, s->energy);
     twolame_set_error_protection(s->glopts, s->error_protection);
 
     twolame_set_num_channels(s->glopts, avctx->channels);
     twolame_set_in_samplerate(s->glopts, avctx->sample_rate);
     twolame_set_out_samplerate(s->glopts, avctx->sample_rate);
     if (avctx->flags & CODEC_FLAG_QSCALE || !avctx->bit_rate) {
         twolame_set_VBR(s->glopts, TRUE);
         twolame_set_VBR_level(s->glopts, avctx->global_quality);
         av_log(avctx, AV_LOG_WARNING, "VBR mode is experimental!\n");
     } else {
         twolame_set_bitrate(s->glopts, avctx->bit_rate / 1000);
     }
 
     if ((ret = twolame_init_params(s->glopts)))
         goto error;
 
     return 0;
 error:
     twolame_encode_close(avctx);
     return ret;
 }
 
 static int twolame_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                                 const AVFrame *frame, int *got_packet_ptr)
 {
     TWOLAMEContext *s = avctx->priv_data;
     int ret;
 

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

         return ret;
 
     if (frame) {
         switch (avctx->sample_fmt) {
         case AV_SAMPLE_FMT_FLT:
             ret = twolame_encode_buffer_float32_interleaved(s->glopts,
                                         frame->data[0],
                                         frame->nb_samples,
                                         avpkt->data, avpkt->size);
             break;
         case AV_SAMPLE_FMT_FLTP:
             ret = twolame_encode_buffer_float32(s->glopts,
                                         frame->data[0], frame->data[1],
                                         frame->nb_samples,
                                         avpkt->data, avpkt->size);
             break;
         case AV_SAMPLE_FMT_S16:
             ret = twolame_encode_buffer_interleaved(s->glopts,
                                         frame->data[0],
                                         frame->nb_samples,
                                         avpkt->data, avpkt->size);
             break;
         case AV_SAMPLE_FMT_S16P:
             ret = twolame_encode_buffer(s->glopts,
                                         frame->data[0], frame->data[1],
                                         frame->nb_samples,
                                         avpkt->data, avpkt->size);
             break;
         default:
             return AVERROR_BUG;
         }
     } else {
         ret = twolame_encode_flush(s->glopts, avpkt->data, avpkt->size);
     }
 
     if (ret > 0) {
         avpkt->duration = ff_samples_to_time_base(avctx, avctx->frame_size);
         if (frame) {
             if (frame->pts != AV_NOPTS_VALUE)
                 avpkt->pts  = frame->pts;
         } else {
             avpkt->pts = s->next_pts;
         }
         if (avpkt->pts != AV_NOPTS_VALUE)
             s->next_pts = avpkt->pts + avpkt->duration;
 
         avpkt->size     = ret;
         *got_packet_ptr = 1;
         return 0;
     }
 
     return ret;
 }
 
 #define OFFSET(x) offsetof(TWOLAMEContext, x)
 #define AE AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {

     { "mode",         "Mpeg Mode", OFFSET(mode), AV_OPT_TYPE_INT, { .i64 = TWOLAME_AUTO_MODE }, TWOLAME_AUTO_MODE, TWOLAME_MONO, AE, "mode"},

     { "auto",         NULL,         0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_AUTO_MODE },          0, 0, AE, "mode" },
     { "stereo",       NULL,         0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_STEREO },             0, 0, AE, "mode" },
     { "joint_stereo", NULL,         0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_JOINT_STEREO },       0, 0, AE, "mode" },
     { "dual_channel", NULL,         0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_DUAL_CHANNEL },       0, 0, AE, "mode" },
     { "mono",         NULL,         0, AV_OPT_TYPE_CONST, { .i64 = TWOLAME_MONO },               0, 0, AE, "mode" },

     { "psymodel",    "Psychoacoustic Model",  OFFSET(psymodel), AV_OPT_TYPE_INT, { .i64 = 3 }, -1, 4, AE},
     { "energy_levels","enable energy levels", OFFSET(energy),   AV_OPT_TYPE_INT, { .i64 = 0 },  0, 1, AE},
     { "error_protection","enable CRC error protection", OFFSET(error_protection), AV_OPT_TYPE_INT, { .i64 = 0 },  0, 1, AE},
     { "copyright",    "set MPEG Audio Copyright flag",  OFFSET(copyright), AV_OPT_TYPE_INT, { .i64 = 0 },  0, 1, AE},
     { "original",     "set MPEG Audio Original flag",   OFFSET(original),  AV_OPT_TYPE_INT, { .i64 = 0 },  0, 1, AE},

     { NULL },
 };
 
 static const AVClass libtwolame_class = {
     .class_name = "libtwolame encoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 AVCodec ff_libtwolame_encoder = {
     .name                  = "libtwolame",
     .type                  = AVMEDIA_TYPE_AUDIO,

     .id                    = AV_CODEC_ID_MP2,

     .priv_data_size        = sizeof(TWOLAMEContext),
     .init                  = twolame_encode_init,
     .encode2               = twolame_encode_frame,
     .close                 = twolame_encode_close,
     .capabilities          = CODEC_CAP_DELAY,
     .sample_fmts           = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
                                                              AV_SAMPLE_FMT_FLTP,
                                                              AV_SAMPLE_FMT_S16,
                                                              AV_SAMPLE_FMT_S16P,
                                                              AV_SAMPLE_FMT_NONE },
     .channel_layouts       = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
                                                   AV_CH_LAYOUT_STEREO,
                                                   0 },
     .supported_samplerates = (const int[]){ 16000, 22050, 24000, 32000, 44100, 48000, 0 },
     .long_name             = NULL_IF_CONFIG_SMALL("libtwolame MP2 (MPEG audio layer 2)"),
     .priv_class            = &libtwolame_class,
 };