/*
  * WebP encoding support via libwebp
  * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.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
  * WebP encoder using libwebp
  */
 
 #include <webp/encode.h>
 
 #include "libavutil/common.h"
 #include "libavutil/frame.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "avcodec.h"
 #include "internal.h"
 
 typedef struct LibWebPContext {
     AVClass *class;         // class for AVOptions
     float quality;          // lossy quality 0 - 100
     int lossless;           // use lossless encoding
     int preset;             // configuration preset
     int chroma_warning;     // chroma linesize mismatch warning has been printed
     int conversion_warning; // pixel format conversion warning has been printed
     WebPConfig config;      // libwebp configuration
 } LibWebPContext;
 
 static int libwebp_error_to_averror(int err)
 {
     switch (err) {
     case VP8_ENC_ERROR_OUT_OF_MEMORY:
     case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:
         return AVERROR(ENOMEM);
     case VP8_ENC_ERROR_NULL_PARAMETER:
     case VP8_ENC_ERROR_INVALID_CONFIGURATION:
     case VP8_ENC_ERROR_BAD_DIMENSION:
         return AVERROR(EINVAL);
     }
     return AVERROR_UNKNOWN;
 }
 
 static av_cold int libwebp_encode_init(AVCodecContext *avctx)
 {
     LibWebPContext *s = avctx->priv_data;
     int ret;
 
     if (avctx->global_quality < 0)
         avctx->global_quality = 75 * FF_QP2LAMBDA;
     s->quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA,
                           0.0f, 100.0f);
 
     if (avctx->compression_level < 0 || avctx->compression_level > 6) {
         av_log(avctx, AV_LOG_WARNING, "invalid compression level: %d\n",
                avctx->compression_level);
         avctx->compression_level = av_clip(avctx->compression_level, 0, 6);
     }
 
     if (s->preset >= WEBP_PRESET_DEFAULT) {
         ret = WebPConfigPreset(&s->config, s->preset, s->quality);
         if (!ret)
             return AVERROR_UNKNOWN;
         s->lossless              = s->config.lossless;
         s->quality               = s->config.quality;
         avctx->compression_level = s->config.method;
     } else {
         ret = WebPConfigInit(&s->config);
         if (!ret)
             return AVERROR_UNKNOWN;
 
         s->config.lossless = s->lossless;
         s->config.quality  = s->quality;
         s->config.method   = avctx->compression_level;
 
         ret = WebPValidateConfig(&s->config);
         if (!ret)
             return AVERROR(EINVAL);
     }
 
     av_log(avctx, AV_LOG_DEBUG, "%s - quality=%.1f method=%d\n",
            s->lossless ? "Lossless" : "Lossy", s->quality,
            avctx->compression_level);
 
     return 0;
 }
 
 static int libwebp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                                 const AVFrame *frame, int *got_packet)
 {
     LibWebPContext *s  = avctx->priv_data;
     AVFrame *alt_frame = NULL;
     WebPPicture *pic = NULL;
     WebPMemoryWriter mw = { 0 };
     int ret;
 
     if (avctx->width > WEBP_MAX_DIMENSION || avctx->height > WEBP_MAX_DIMENSION) {
         av_log(avctx, AV_LOG_ERROR, "Picture size is too large. Max is %dx%d.\n",
                WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);
         return AVERROR(EINVAL);
     }
 
     pic = av_malloc(sizeof(*pic));
     if (!pic)
         return AVERROR(ENOMEM);
 
     ret = WebPPictureInit(pic);
     if (!ret) {
         ret = AVERROR_UNKNOWN;
         goto end;
     }
     pic->width  = avctx->width;
     pic->height = avctx->height;
 
     if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
         if (!s->lossless) {
             /* libwebp will automatically convert RGB input to YUV when
                encoding lossy. */
             if (!s->conversion_warning) {
                 av_log(avctx, AV_LOG_WARNING,
                        "Using libwebp for RGB-to-YUV conversion. You may want "
                        "to consider passing in YUV instead for lossy "
                        "encoding.\n");
                 s->conversion_warning = 1;
             }
         }
         pic->use_argb    = 1;
         pic->argb        = (uint32_t *)frame->data[0];
         pic->argb_stride = frame->linesize[0] / 4;
     } else {
         if (frame->linesize[1] != frame->linesize[2]) {
             if (!s->chroma_warning) {
                 av_log(avctx, AV_LOG_WARNING,
                        "Copying frame due to differing chroma linesizes.\n");
                 s->chroma_warning = 1;
             }
             alt_frame = av_frame_alloc();
             if (!alt_frame) {
                 ret = AVERROR(ENOMEM);
                 goto end;
             }
             alt_frame->width  = frame->width;
             alt_frame->height = frame->height;
             alt_frame->format = frame->format;
             ret = av_frame_get_buffer(alt_frame, 32);
             if (ret < 0)
                 goto end;

             av_frame_copy(alt_frame, frame);

             frame = alt_frame;
         }
         pic->use_argb  = 0;
         pic->y         = frame->data[0];
         pic->u         = frame->data[1];
         pic->v         = frame->data[2];
         pic->y_stride  = frame->linesize[0];
         pic->uv_stride = frame->linesize[1];
         if (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) {
             pic->colorspace = WEBP_YUV420A;
             pic->a          = frame->data[3];
             pic->a_stride   = frame->linesize[3];
         } else {
             pic->colorspace = WEBP_YUV420;
         }
 
         if (s->lossless) {
             /* We do not have a way to automatically prioritize RGB over YUV
                in automatic pixel format conversion based on whether we're
                encoding lossless or lossy, so we do conversion with libwebp as
                a convenience. */
             if (!s->conversion_warning) {
                 av_log(avctx, AV_LOG_WARNING,
                        "Using libwebp for YUV-to-RGB conversion. You may want "
                        "to consider passing in RGB instead for lossless "
                        "encoding.\n");
                 s->conversion_warning = 1;
             }
 
 #if (WEBP_ENCODER_ABI_VERSION <= 0x201)
             /* libwebp should do the conversion automatically, but there is a
                bug that causes it to return an error instead, so a work-around
                is required.
                See https://code.google.com/p/webp/issues/detail?id=178 */
             pic->memory_ = (void*)1;  /* something non-null */
             ret = WebPPictureYUVAToARGB(pic);
             if (!ret) {
                 av_log(avctx, AV_LOG_ERROR,
                        "WebPPictureYUVAToARGB() failed with error: %d\n",
                        pic->error_code);
                 ret = libwebp_error_to_averror(pic->error_code);
                 goto end;
             }
             pic->memory_ = NULL;  /* restore pointer */
 #endif
         }
     }
 
     WebPMemoryWriterInit(&mw);
     pic->custom_ptr = &mw;
     pic->writer     = WebPMemoryWrite;
 
     ret = WebPEncode(&s->config, pic);
     if (!ret) {
         av_log(avctx, AV_LOG_ERROR, "WebPEncode() failed with error: %d\n",
                pic->error_code);
         ret = libwebp_error_to_averror(pic->error_code);
         goto end;
     }
 
     ret = ff_alloc_packet(pkt, mw.size);
     if (ret < 0)
         goto end;
     memcpy(pkt->data, mw.mem, mw.size);
 
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
 
 end:
     free(mw.mem); /* must use free() according to libwebp documentation */
     WebPPictureFree(pic);
     av_freep(&pic);
     av_frame_free(&alt_frame);
 
     return ret;
 }
 
 #define OFFSET(x) offsetof(LibWebPContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "lossless",   "Use lossless mode",       OFFSET(lossless), AV_OPT_TYPE_INT,   { .i64 =  0 },  0, 1,                           VE           },
     { "preset",     "Configuration preset",    OFFSET(preset),   AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, WEBP_PRESET_TEXT,            VE, "preset" },
     { "none",       "do not use a preset",                              0, AV_OPT_TYPE_CONST, { .i64 = -1                  }, 0, 0, VE, "preset" },
     { "default",    "default preset",                                   0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DEFAULT }, 0, 0, VE, "preset" },
     { "picture",    "digital picture, like portrait, inner shot",       0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PICTURE }, 0, 0, VE, "preset" },
     { "photo",      "outdoor photograph, with natural lighting",        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PHOTO   }, 0, 0, VE, "preset" },
     { "drawing",    "hand or line drawing, with high-contrast details", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DRAWING }, 0, 0, VE, "preset" },
     { "icon",       "small-sized colorful images",                      0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_ICON    }, 0, 0, VE, "preset" },
     { "text",       "text-like",                                        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_TEXT    }, 0, 0, VE, "preset" },
     { NULL },
 };
 
 static const AVClass class = {
     .class_name = "libwebp",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 
 static const AVCodecDefault libwebp_defaults[] = {
     { "compression_level",  "4"  },
     { "global_quality",     "-1" },
     { NULL },
 };
 
 AVCodec ff_libwebp_encoder = {
     .name           = "libwebp",
     .long_name      = NULL_IF_CONFIG_SMALL("libwebp WebP image"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_WEBP,
     .priv_data_size = sizeof(LibWebPContext),
     .init           = libwebp_encode_init,
     .encode2        = libwebp_encode_frame,
     .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,
 };