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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 
30 const 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
38 static 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 
54 const 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 
61 const 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 
ff_libwebp_error_to_averror(int err)67 int 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 
ff_libwebp_encode_init_common(AVCodecContext * avctx)81 av_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 
ff_libwebp_get_frame(AVCodecContext * avctx,LibWebPContextCommon * s,const AVFrame * frame,AVFrame ** alt_frame_ptr,WebPPicture ** pic_ptr)124 int 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     }
290 end:
291     return ret;
292 }
293