/*
  * WebP encoding support via libwebp
  * Copyright (c) 2015 Urvang Joshi
  *
  * 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
  * WebP encoder using libwebp (WebPAnimEncoder API)
  */
 
 #include "config.h"
 #include "libwebpenc_common.h"
 
 #include <webp/mux.h>
 
 typedef struct LibWebPAnimContext {
     LibWebPContextCommon cc;
     WebPAnimEncoder *enc;     // the main AnimEncoder object
     int64_t prev_frame_pts;   // pts of the previously encoded frame.
     int done;                 // If true, we have assembled the bitstream already
 } LibWebPAnimContext;
 
 static av_cold int libwebp_anim_encode_init(AVCodecContext *avctx)
 {
     int ret = ff_libwebp_encode_init_common(avctx);
     if (!ret) {
         LibWebPAnimContext *s = avctx->priv_data;

         WebPAnimEncoderOptions enc_options = { { 0 } };

         WebPAnimEncoderOptionsInit(&enc_options);

         enc_options.verbose = av_log_get_level() >= AV_LOG_VERBOSE;

         // TODO(urvang): Expose some options on command-line perhaps.
         s->enc = WebPAnimEncoderNew(avctx->width, avctx->height, &enc_options);
         if (!s->enc)
             return AVERROR(EINVAL);
         s->prev_frame_pts = -1;
         s->done = 0;
     }
     return ret;
 }
 
 static int libwebp_anim_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                                      const AVFrame *frame, int *got_packet) {
     LibWebPAnimContext *s = avctx->priv_data;
     int ret;
 
     if (!frame) {
         if (s->done) {  // Second flush: return empty package to denote finish.
             *got_packet = 0;
             return 0;
         } else {  // First flush: assemble bitstream and return it.
             WebPData assembled_data = { 0 };
             ret = WebPAnimEncoderAssemble(s->enc, &assembled_data);
             if (ret) {

                 ret = ff_alloc_packet2(avctx, pkt, assembled_data.size, assembled_data.size);

                 if (ret < 0)
                     return ret;
                 memcpy(pkt->data, assembled_data.bytes, assembled_data.size);
                 s->done = 1;
                 pkt->flags |= AV_PKT_FLAG_KEY;
                 pkt->pts = pkt->dts = s->prev_frame_pts + 1;
                 *got_packet = 1;
                 return 0;
             } else {
                 av_log(s, AV_LOG_ERROR,
                        "WebPAnimEncoderAssemble() failed with error: %d\n",
                        VP8_ENC_ERROR_OUT_OF_MEMORY);
                 return AVERROR(ENOMEM);
             }
         }
     } else {
         int timestamp_ms;
         WebPPicture *pic = NULL;
         AVFrame *alt_frame = NULL;
         ret = ff_libwebp_get_frame(avctx, &s->cc, frame, &alt_frame, &pic);
         if (ret < 0)
             goto end;
 
         timestamp_ms =
             avctx->time_base.num * frame->pts * 1000 / avctx->time_base.den;
         ret = WebPAnimEncoderAdd(s->enc, pic, timestamp_ms, &s->cc.config);
         if (!ret) {
                 av_log(avctx, AV_LOG_ERROR,
                        "Encoding WebP frame failed with error: %d\n",
                    pic->error_code);
             ret = ff_libwebp_error_to_averror(pic->error_code);
             goto end;
         }
 
         pkt->pts = pkt->dts = frame->pts;
         s->prev_frame_pts = frame->pts;  // Save for next frame.
         ret = 0;
         *got_packet = 1;
 
 end:
         WebPPictureFree(pic);
         av_freep(&pic);
         av_frame_free(&alt_frame);
         return ret;
     }
 }
 
 static int libwebp_anim_encode_close(AVCodecContext *avctx)
 {

     LibWebPAnimContext *s = avctx->priv_data;
     av_frame_free(&s->cc.ref);
     WebPAnimEncoderDelete(s->enc);
 
     return 0;

 }
 

 static const AVClass class = {
     .class_name = "libwebp_anim",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 AVCodec ff_libwebp_anim_encoder = {
     .name           = "libwebp_anim",
     .long_name      = NULL_IF_CONFIG_SMALL("libwebp WebP image"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_WEBP,
     .priv_data_size = sizeof(LibWebPAnimContext),
     .init           = libwebp_anim_encode_init,
     .encode2        = libwebp_anim_encode_frame,
     .close          = libwebp_anim_encode_close,

     .capabilities   = AV_CODEC_CAP_DELAY,

     .pix_fmts       = (const enum AVPixelFormat[]) {
         AV_PIX_FMT_RGB32,
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_NONE
     },
     .priv_class     = &class,
     .defaults       = libwebp_defaults,
 };