/*
  * codec2 encoder/decoder using libcodec2
  * Copyright (c) 2017 Tomas Härdin
  *
  * 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 <codec2/codec2.h>
 #include "avcodec.h"
 #include "libavutil/opt.h"
 #include "internal.h"
 #include "codec2utils.h"
 
 typedef struct {
     const AVClass *class;
     struct CODEC2 *codec;
     int mode;
 } LibCodec2Context;
 
 static const AVOption options[] = {
     //not AV_OPT_FLAG_DECODING_PARAM since mode should come from the demuxer
     //1300 (aka FreeDV 1600) is the most common mode on-the-air, default to it here as well
     AVPRIV_CODEC2_AVOPTIONS("codec2 mode", LibCodec2Context, 0, 4 /*CODEC2_MODE_1300*/, AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_ENCODING_PARAM),
     { NULL },
 };
 
 static const AVClass libcodec2_enc_class = {
     .class_name = "libcodec2 encoder",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 static const AVClass libcodec2_dec_class = {
     .class_name = "libcodec2 decoder",
     .item_name  = av_default_item_name,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 static av_cold int libcodec2_init_common(AVCodecContext *avctx, int mode)
 {
     LibCodec2Context *c2 = avctx->priv_data;
     //Grab mode name from options, unless it's some weird number.
     const char *modename = mode >= 0 && mode <= AVPRIV_CODEC2_MODE_MAX ? options[mode+1].name : "?";
 
     c2->codec = codec2_create(mode);
     if (!c2->codec) {
         //Out of memory or unsupported mode. The latter seems most likely,
         //but we can't tell for sure with the current API.
         goto libcodec2_init_common_error;
     }
 
     avctx->frame_size = codec2_samples_per_frame(c2->codec);
     avctx->block_align = (codec2_bits_per_frame(c2->codec) + 7) / 8;
 
     if (avctx->frame_size <= 0 || avctx->block_align <= 0) {
         //codec2_create() may succeed for some modes but still fail at codec2_samples_per_frame()
         //example is -mode 700C on libcodec2 0.4
         codec2_destroy(c2->codec);
         c2->codec = NULL;
         goto libcodec2_init_common_error;
     }
 
     codec2_set_natural_or_gray(c2->codec, 1);
 
     return 0;
 
 libcodec2_init_common_error:
     av_log(avctx, AV_LOG_ERROR,
         "Mode %i (%s) not supported with the linked version of libcodec2\n",
         mode, modename);
     return AVERROR(EINVAL);
 }
 
 static av_cold int libcodec2_init_decoder(AVCodecContext *avctx)
 {
     avctx->sample_rate      = 8000;
     avctx->channels         = 1;
     avctx->sample_fmt       = AV_SAMPLE_FMT_S16;
     avctx->channel_layout   = AV_CH_LAYOUT_MONO;
 
     if (avctx->extradata_size != AVPRIV_CODEC2_EXTRADATA_SIZE) {
         av_log(avctx, AV_LOG_ERROR, "must have exactly %i bytes of extradata (got %i)\n",
                AVPRIV_CODEC2_EXTRADATA_SIZE, avctx->extradata_size);
         return AVERROR_INVALIDDATA;
     }
 
     return libcodec2_init_common(avctx, avpriv_codec2_mode_from_extradata(avctx->extradata));
 }
 
 static av_cold int libcodec2_init_encoder(AVCodecContext *avctx)
 {
     LibCodec2Context *c2 = avctx->priv_data;
 
     //will need to be smarter once we get wideband support
     if (avctx->sample_rate != 8000 ||
         avctx->channels != 1 ||
         avctx->sample_fmt != AV_SAMPLE_FMT_S16) {
         av_log(avctx, AV_LOG_ERROR, "only 8 kHz 16-bit mono allowed\n");
         return AVERROR(EINVAL);
     }
 
     avctx->extradata = av_mallocz(AVPRIV_CODEC2_EXTRADATA_SIZE + AV_INPUT_BUFFER_PADDING_SIZE);
     if (!avctx->extradata) {
         return AVERROR(ENOMEM);
     }
 
     avctx->extradata_size = AVPRIV_CODEC2_EXTRADATA_SIZE;
     avpriv_codec2_make_extradata(avctx->extradata, c2->mode);
 
     return libcodec2_init_common(avctx, c2->mode);
 }
 
 static av_cold int libcodec2_close(AVCodecContext *avctx)
 {
     LibCodec2Context *c2 = avctx->priv_data;
 
     codec2_destroy(c2->codec);
     return 0;
 }
 
 static int libcodec2_decode(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *pkt)
 {
     LibCodec2Context *c2 = avctx->priv_data;
     AVFrame *frame = data;
     int ret, nframes, i;
     uint8_t *input;
     int16_t *output;
 
     nframes           = pkt->size / avctx->block_align;
     frame->nb_samples = avctx->frame_size * nframes;
 
     ret = ff_get_buffer(avctx, frame, 0);
     if (ret < 0) {
         return ret;
     }
 
     input  = pkt->data;
     output = (int16_t *)frame->data[0];
 
     for (i = 0; i < nframes; i++) {
         codec2_decode(c2->codec, output, input);
         input  += avctx->block_align;
         output += avctx->frame_size;
     }
 
     *got_frame_ptr = nframes > 0;
     return nframes * avctx->block_align;
 }
 
 static int libcodec2_encode(AVCodecContext *avctx, AVPacket *avpkt,
                             const AVFrame *frame, int *got_packet_ptr)
 {
     LibCodec2Context *c2 = avctx->priv_data;
     int16_t *samples = (int16_t *)frame->data[0];
 
     int ret = ff_alloc_packet2(avctx, avpkt, avctx->block_align, 0);
     if (ret < 0) {
         return ret;
     }
 
     codec2_encode(c2->codec, avpkt->data, samples);
     *got_packet_ptr = 1;
 
     return 0;
 }
 
 AVCodec ff_libcodec2_decoder = {
     .name                   = "libcodec2",
     .long_name              = NULL_IF_CONFIG_SMALL("codec2 decoder using libcodec2"),
     .type                   = AVMEDIA_TYPE_AUDIO,
     .id                     = AV_CODEC_ID_CODEC2,
     .priv_data_size         = sizeof(LibCodec2Context),
     .init                   = libcodec2_init_decoder,
     .close                  = libcodec2_close,
     .decode                 = libcodec2_decode,
     .capabilities           = 0,
     .supported_samplerates  = (const int[]){ 8000, 0 },
     .sample_fmts            = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
     .channel_layouts        = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
     .priv_class             = &libcodec2_dec_class,
 };
 
 AVCodec ff_libcodec2_encoder = {
     .name                   = "libcodec2",
     .long_name              = NULL_IF_CONFIG_SMALL("codec2 encoder using libcodec2"),
     .type                   = AVMEDIA_TYPE_AUDIO,
     .id                     = AV_CODEC_ID_CODEC2,
     .priv_data_size         = sizeof(LibCodec2Context),
     .init                   = libcodec2_init_encoder,
     .close                  = libcodec2_close,
     .encode2                = libcodec2_encode,
     .capabilities           = 0,
     .supported_samplerates  = (const int[]){ 8000, 0 },
     .sample_fmts            = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_NONE },
     .channel_layouts        = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
     .priv_class             = &libcodec2_enc_class,
 };