/*
* 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,
};