1/*
2 * WebP encoding support via libwebp
3 * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * WebP encoder using libwebp: common structs and methods.
25 */
26
27#include "libavutil/opt.h"
28#include "libwebpenc_common.h"
29
30const FFCodecDefault ff_libwebp_defaults[] = {
31    { "compression_level",  "4"  },
32    { "global_quality",     "-1" },
33    { NULL },
34};
35
36#define OFFSET(x) offsetof(LibWebPContextCommon, x)
37#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
38static const AVOption options[] = {
39    { "lossless",   "Use lossless mode",       OFFSET(lossless), AV_OPT_TYPE_INT,   { .i64 =  0 },  0, 1,                           VE           },
40    { "preset",     "Configuration preset",    OFFSET(preset),   AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, WEBP_PRESET_TEXT,            VE, "preset" },
41    { "none",       "do not use a preset",                              0, AV_OPT_TYPE_CONST, { .i64 = -1                  }, 0, 0, VE, "preset" },
42    { "default",    "default preset",                                   0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DEFAULT }, 0, 0, VE, "preset" },
43    { "picture",    "digital picture, like portrait, inner shot",       0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PICTURE }, 0, 0, VE, "preset" },
44    { "photo",      "outdoor photograph, with natural lighting",        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PHOTO   }, 0, 0, VE, "preset" },
45    { "drawing",    "hand or line drawing, with high-contrast details", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DRAWING }, 0, 0, VE, "preset" },
46    { "icon",       "small-sized colorful images",                      0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_ICON    }, 0, 0, VE, "preset" },
47    { "text",       "text-like",                                        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_TEXT    }, 0, 0, VE, "preset" },
48    { "cr_threshold","Conditional replenishment threshold",     OFFSET(cr_threshold), AV_OPT_TYPE_INT, { .i64 =  0  },  0, INT_MAX, VE           },
49    { "cr_size"     ,"Conditional replenishment block size",    OFFSET(cr_size)     , AV_OPT_TYPE_INT, { .i64 =  16 },  0, 256,     VE           },
50    { "quality"     ,"Quality",                OFFSET(quality),  AV_OPT_TYPE_FLOAT, { .dbl =  75 }, 0, 100,                         VE           },
51    { NULL },
52};
53
54const AVClass ff_libwebpenc_class = {
55    .class_name = "libwebp encoder",
56    .item_name  = av_default_item_name,
57    .option     = options,
58    .version    = LIBAVUTIL_VERSION_INT,
59};
60
61const enum AVPixelFormat ff_libwebpenc_pix_fmts[] = {
62    AV_PIX_FMT_RGB32,
63    AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,
64    AV_PIX_FMT_NONE
65};
66
67int ff_libwebp_error_to_averror(int err)
68{
69    switch (err) {
70    case VP8_ENC_ERROR_OUT_OF_MEMORY:
71    case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:
72        return AVERROR(ENOMEM);
73    case VP8_ENC_ERROR_NULL_PARAMETER:
74    case VP8_ENC_ERROR_INVALID_CONFIGURATION:
75    case VP8_ENC_ERROR_BAD_DIMENSION:
76        return AVERROR(EINVAL);
77    }
78    return AVERROR_UNKNOWN;
79}
80
81av_cold int ff_libwebp_encode_init_common(AVCodecContext *avctx)
82{
83    LibWebPContextCommon *s = avctx->priv_data;
84    int ret;
85
86    if (avctx->global_quality >= 0)
87        s->quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA,
88                              0.0f, 100.0f);
89
90    if (avctx->compression_level < 0 || avctx->compression_level > 6) {
91        av_log(avctx, AV_LOG_WARNING, "invalid compression level: %d\n",
92               avctx->compression_level);
93        avctx->compression_level = av_clip(avctx->compression_level, 0, 6);
94    }
95
96    if (s->preset >= WEBP_PRESET_DEFAULT) {
97        ret = WebPConfigPreset(&s->config, s->preset, s->quality);
98        if (!ret)
99            return AVERROR_UNKNOWN;
100        s->lossless              = s->config.lossless;
101        s->quality               = s->config.quality;
102        avctx->compression_level = s->config.method;
103    } else {
104        ret = WebPConfigInit(&s->config);
105        if (!ret)
106            return AVERROR_UNKNOWN;
107
108        s->config.lossless = s->lossless;
109        s->config.quality  = s->quality;
110        s->config.method   = avctx->compression_level;
111
112        ret = WebPValidateConfig(&s->config);
113        if (!ret)
114            return AVERROR(EINVAL);
115    }
116
117    av_log(avctx, AV_LOG_DEBUG, "%s - quality=%.1f method=%d\n",
118           s->lossless ? "Lossless" : "Lossy", s->quality,
119           avctx->compression_level);
120
121    return 0;
122}
123
124int ff_libwebp_get_frame(AVCodecContext *avctx, LibWebPContextCommon *s,
125                         const AVFrame *frame, AVFrame **alt_frame_ptr,
126                         WebPPicture **pic_ptr) {
127    int ret;
128    WebPPicture *pic = NULL;
129    AVFrame *alt_frame = NULL;
130
131    if (avctx->width > WEBP_MAX_DIMENSION || avctx->height > WEBP_MAX_DIMENSION) {
132        av_log(avctx, AV_LOG_ERROR, "Picture size is too large. Max is %dx%d.\n",
133               WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);
134        return AVERROR(EINVAL);
135    }
136
137    *pic_ptr = av_malloc(sizeof(*pic));
138    pic = *pic_ptr;
139    if (!pic)
140        return AVERROR(ENOMEM);
141
142    ret = WebPPictureInit(pic);
143    if (!ret) {
144        ret = AVERROR_UNKNOWN;
145        goto end;
146    }
147    pic->width  = avctx->width;
148    pic->height = avctx->height;
149
150    if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
151        if (!s->lossless) {
152            /* libwebp will automatically convert RGB input to YUV when
153               encoding lossy. */
154            if (!s->conversion_warning) {
155                av_log(avctx, AV_LOG_WARNING,
156                       "Using libwebp for RGB-to-YUV conversion. You may want "
157                       "to consider passing in YUV instead for lossy "
158                       "encoding.\n");
159                s->conversion_warning = 1;
160            }
161        }
162        pic->use_argb    = 1;
163        pic->argb        = (uint32_t *)frame->data[0];
164        pic->argb_stride = frame->linesize[0] / 4;
165    } else {
166        if (frame->linesize[1] != frame->linesize[2] || s->cr_threshold) {
167            if (!s->chroma_warning && !s->cr_threshold) {
168                av_log(avctx, AV_LOG_WARNING,
169                       "Copying frame due to differing chroma linesizes.\n");
170                s->chroma_warning = 1;
171            }
172            *alt_frame_ptr = av_frame_alloc();
173            alt_frame = *alt_frame_ptr;
174            if (!alt_frame) {
175                ret = AVERROR(ENOMEM);
176                goto end;
177            }
178            alt_frame->width  = frame->width;
179            alt_frame->height = frame->height;
180            alt_frame->format = frame->format;
181            if (s->cr_threshold)
182                alt_frame->format = AV_PIX_FMT_YUVA420P;
183            ret = av_frame_get_buffer(alt_frame, 0);
184            if (ret < 0)
185                goto end;
186            alt_frame->format = frame->format;
187            av_frame_copy(alt_frame, frame);
188            frame = alt_frame;
189            if (s->cr_threshold) {
190                int x,y, x2, y2, p;
191                int bs = s->cr_size;
192
193                if (!s->ref) {
194                    s->ref = av_frame_clone(frame);
195                    if (!s->ref) {
196                        ret = AVERROR(ENOMEM);
197                        goto end;
198                    }
199                }
200
201                alt_frame->format = AV_PIX_FMT_YUVA420P;
202                for (y = 0; y < frame->height; y+= bs) {
203                    for (x = 0; x < frame->width; x+= bs) {
204                        int skip;
205                        int sse = 0;
206                        for (p = 0; p < 3; p++) {
207                            int bs2 = bs >> !!p;
208                            int w = AV_CEIL_RSHIFT(frame->width , !!p);
209                            int h = AV_CEIL_RSHIFT(frame->height, !!p);
210                            int xs = x >> !!p;
211                            int ys = y >> !!p;
212                            for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
213                                for (x2 = xs; x2 < FFMIN(xs + bs2, w); x2++) {
214                                    int diff =  frame->data[p][frame->linesize[p] * y2 + x2]
215                                              -s->ref->data[p][frame->linesize[p] * y2 + x2];
216                                    sse += diff*diff;
217                                }
218                            }
219                        }
220                        skip = sse < s->cr_threshold && frame->data[3] != s->ref->data[3];
221                        if (!skip)
222                            for (p = 0; p < 3; p++) {
223                                int bs2 = bs >> !!p;
224                                int w = AV_CEIL_RSHIFT(frame->width , !!p);
225                                int h = AV_CEIL_RSHIFT(frame->height, !!p);
226                                int xs = x >> !!p;
227                                int ys = y >> !!p;
228                                for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
229                                    memcpy(&s->ref->data[p][frame->linesize[p] * y2 + xs],
230                                            & frame->data[p][frame->linesize[p] * y2 + xs], FFMIN(bs2, w-xs));
231                                }
232                            }
233                        for (y2 = y; y2 < FFMIN(y+bs, frame->height); y2++) {
234                            memset(&frame->data[3][frame->linesize[3] * y2 + x],
235                                    skip ? 0 : 255,
236                                    FFMIN(bs, frame->width-x));
237                        }
238                    }
239                }
240            }
241        }
242
243        pic->use_argb  = 0;
244        pic->y         = frame->data[0];
245        pic->u         = frame->data[1];
246        pic->v         = frame->data[2];
247        pic->y_stride  = frame->linesize[0];
248        pic->uv_stride = frame->linesize[1];
249        if (frame->format == AV_PIX_FMT_YUVA420P) {
250            pic->colorspace = WEBP_YUV420A;
251            pic->a          = frame->data[3];
252            pic->a_stride   = frame->linesize[3];
253            if (alt_frame)
254                WebPCleanupTransparentArea(pic);
255        } else {
256            pic->colorspace = WEBP_YUV420;
257        }
258
259        if (s->lossless) {
260            /* We do not have a way to automatically prioritize RGB over YUV
261               in automatic pixel format conversion based on whether we're
262               encoding lossless or lossy, so we do conversion with libwebp as
263               a convenience. */
264            if (!s->conversion_warning) {
265                av_log(avctx, AV_LOG_WARNING,
266                       "Using libwebp for YUV-to-RGB conversion. You may want "
267                       "to consider passing in RGB instead for lossless "
268                       "encoding.\n");
269                s->conversion_warning = 1;
270            }
271
272#if (WEBP_ENCODER_ABI_VERSION <= 0x201)
273            /* libwebp should do the conversion automatically, but there is a
274               bug that causes it to return an error instead, so a work-around
275               is required.
276               See https://code.google.com/p/webp/issues/detail?id=178 */
277            pic->memory_ = (void*)1;  /* something non-null */
278            ret = WebPPictureYUVAToARGB(pic);
279            if (!ret) {
280                av_log(avctx, AV_LOG_ERROR,
281                       "WebPPictureYUVAToARGB() failed with error: %d\n",
282                       pic->error_code);
283                ret = libwebp_error_to_averror(pic->error_code);
284                goto end;
285            }
286            pic->memory_ = NULL;  /* restore pointer */
287#endif
288        }
289    }
290end:
291    return ret;
292}
293