FFmpeg
libwebpenc_common.c
Go to the documentation of this file.
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 "libwebpenc_common.h"
28 
30 {
31  switch (err) {
32  case VP8_ENC_ERROR_OUT_OF_MEMORY:
33  case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:
34  return AVERROR(ENOMEM);
35  case VP8_ENC_ERROR_NULL_PARAMETER:
36  case VP8_ENC_ERROR_INVALID_CONFIGURATION:
37  case VP8_ENC_ERROR_BAD_DIMENSION:
38  return AVERROR(EINVAL);
39  }
40  return AVERROR_UNKNOWN;
41 }
42 
44 {
46  int ret;
47 
48  if (avctx->global_quality >= 0)
49  s->quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA,
50  0.0f, 100.0f);
51 
52  if (avctx->compression_level < 0 || avctx->compression_level > 6) {
53  av_log(avctx, AV_LOG_WARNING, "invalid compression level: %d\n",
54  avctx->compression_level);
55  avctx->compression_level = av_clip(avctx->compression_level, 0, 6);
56  }
57 
58  if (s->preset >= WEBP_PRESET_DEFAULT) {
59  ret = WebPConfigPreset(&s->config, s->preset, s->quality);
60  if (!ret)
61  return AVERROR_UNKNOWN;
62  s->lossless = s->config.lossless;
63  s->quality = s->config.quality;
64  avctx->compression_level = s->config.method;
65  } else {
66  ret = WebPConfigInit(&s->config);
67  if (!ret)
68  return AVERROR_UNKNOWN;
69 
70  s->config.lossless = s->lossless;
71  s->config.quality = s->quality;
72  s->config.method = avctx->compression_level;
73 
74  ret = WebPValidateConfig(&s->config);
75  if (!ret)
76  return AVERROR(EINVAL);
77  }
78 
79  av_log(avctx, AV_LOG_DEBUG, "%s - quality=%.1f method=%d\n",
80  s->lossless ? "Lossless" : "Lossy", s->quality,
81  avctx->compression_level);
82 
83  return 0;
84 }
85 
87  const AVFrame *frame, AVFrame **alt_frame_ptr,
88  WebPPicture **pic_ptr) {
89  int ret;
90  WebPPicture *pic = NULL;
91  AVFrame *alt_frame = NULL;
92 
93  if (avctx->width > WEBP_MAX_DIMENSION || avctx->height > WEBP_MAX_DIMENSION) {
94  av_log(avctx, AV_LOG_ERROR, "Picture size is too large. Max is %dx%d.\n",
95  WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);
96  return AVERROR(EINVAL);
97  }
98 
99  *pic_ptr = av_malloc(sizeof(*pic));
100  pic = *pic_ptr;
101  if (!pic)
102  return AVERROR(ENOMEM);
103 
104  ret = WebPPictureInit(pic);
105  if (!ret) {
106  ret = AVERROR_UNKNOWN;
107  goto end;
108  }
109  pic->width = avctx->width;
110  pic->height = avctx->height;
111 
112  if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
113  if (!s->lossless) {
114  /* libwebp will automatically convert RGB input to YUV when
115  encoding lossy. */
116  if (!s->conversion_warning) {
117  av_log(avctx, AV_LOG_WARNING,
118  "Using libwebp for RGB-to-YUV conversion. You may want "
119  "to consider passing in YUV instead for lossy "
120  "encoding.\n");
121  s->conversion_warning = 1;
122  }
123  }
124  pic->use_argb = 1;
125  pic->argb = (uint32_t *)frame->data[0];
126  pic->argb_stride = frame->linesize[0] / 4;
127  } else {
128  if (frame->linesize[1] != frame->linesize[2] || s->cr_threshold) {
129  if (!s->chroma_warning && !s->cr_threshold) {
130  av_log(avctx, AV_LOG_WARNING,
131  "Copying frame due to differing chroma linesizes.\n");
132  s->chroma_warning = 1;
133  }
134  *alt_frame_ptr = av_frame_alloc();
135  alt_frame = *alt_frame_ptr;
136  if (!alt_frame) {
137  ret = AVERROR(ENOMEM);
138  goto end;
139  }
140  alt_frame->width = frame->width;
141  alt_frame->height = frame->height;
142  alt_frame->format = frame->format;
143  if (s->cr_threshold)
144  alt_frame->format = AV_PIX_FMT_YUVA420P;
145  ret = av_frame_get_buffer(alt_frame, 32);
146  if (ret < 0)
147  goto end;
148  alt_frame->format = frame->format;
149  av_frame_copy(alt_frame, frame);
150  frame = alt_frame;
151  if (s->cr_threshold) {
152  int x,y, x2, y2, p;
153  int bs = s->cr_size;
154 
155  if (!s->ref) {
156  s->ref = av_frame_clone(frame);
157  if (!s->ref) {
158  ret = AVERROR(ENOMEM);
159  goto end;
160  }
161  }
162 
163  alt_frame->format = AV_PIX_FMT_YUVA420P;
164  for (y = 0; y < frame->height; y+= bs) {
165  for (x = 0; x < frame->width; x+= bs) {
166  int skip;
167  int sse = 0;
168  for (p = 0; p < 3; p++) {
169  int bs2 = bs >> !!p;
170  int w = AV_CEIL_RSHIFT(frame->width , !!p);
171  int h = AV_CEIL_RSHIFT(frame->height, !!p);
172  int xs = x >> !!p;
173  int ys = y >> !!p;
174  for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
175  for (x2 = xs; x2 < FFMIN(xs + bs2, w); x2++) {
176  int diff = frame->data[p][frame->linesize[p] * y2 + x2]
177  -s->ref->data[p][frame->linesize[p] * y2 + x2];
178  sse += diff*diff;
179  }
180  }
181  }
182  skip = sse < s->cr_threshold && frame->data[3] != s->ref->data[3];
183  if (!skip)
184  for (p = 0; p < 3; p++) {
185  int bs2 = bs >> !!p;
186  int w = AV_CEIL_RSHIFT(frame->width , !!p);
187  int h = AV_CEIL_RSHIFT(frame->height, !!p);
188  int xs = x >> !!p;
189  int ys = y >> !!p;
190  for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {
191  memcpy(&s->ref->data[p][frame->linesize[p] * y2 + xs],
192  & frame->data[p][frame->linesize[p] * y2 + xs], FFMIN(bs2, w-xs));
193  }
194  }
195  for (y2 = y; y2 < FFMIN(y+bs, frame->height); y2++) {
196  memset(&frame->data[3][frame->linesize[3] * y2 + x],
197  skip ? 0 : 255,
198  FFMIN(bs, frame->width-x));
199  }
200  }
201  }
202  }
203  }
204 
205  pic->use_argb = 0;
206  pic->y = frame->data[0];
207  pic->u = frame->data[1];
208  pic->v = frame->data[2];
209  pic->y_stride = frame->linesize[0];
210  pic->uv_stride = frame->linesize[1];
211  if (frame->format == AV_PIX_FMT_YUVA420P) {
212  pic->colorspace = WEBP_YUV420A;
213  pic->a = frame->data[3];
214  pic->a_stride = frame->linesize[3];
215  if (alt_frame)
216  WebPCleanupTransparentArea(pic);
217  } else {
218  pic->colorspace = WEBP_YUV420;
219  }
220 
221  if (s->lossless) {
222  /* We do not have a way to automatically prioritize RGB over YUV
223  in automatic pixel format conversion based on whether we're
224  encoding lossless or lossy, so we do conversion with libwebp as
225  a convenience. */
226  if (!s->conversion_warning) {
227  av_log(avctx, AV_LOG_WARNING,
228  "Using libwebp for YUV-to-RGB conversion. You may want "
229  "to consider passing in RGB instead for lossless "
230  "encoding.\n");
231  s->conversion_warning = 1;
232  }
233 
234 #if (WEBP_ENCODER_ABI_VERSION <= 0x201)
235  /* libwebp should do the conversion automatically, but there is a
236  bug that causes it to return an error instead, so a work-around
237  is required.
238  See https://code.google.com/p/webp/issues/detail?id=178 */
239  pic->memory_ = (void*)1; /* something non-null */
240  ret = WebPPictureYUVAToARGB(pic);
241  if (!ret) {
242  av_log(avctx, AV_LOG_ERROR,
243  "WebPPictureYUVAToARGB() failed with error: %d\n",
244  pic->error_code);
245  ret = libwebp_error_to_averror(pic->error_code);
246  goto end;
247  }
248  pic->memory_ = NULL; /* restore pointer */
249 #endif
250  }
251  }
252 end:
253  return ret;
254 }
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1775
static int sse(MpegEncContext *s, uint8_t *src1, uint8_t *src2, int w, int h, int stride)
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:101
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
#define av_log(a,...)
int width
Definition: frame.h:353
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
WebP encoder using libwebp: common structs and methods.
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
int ff_libwebp_get_frame(AVCodecContext *avctx, LibWebPContextCommon *s, const AVFrame *frame, AVFrame **alt_frame_ptr, WebPPicture **pic_ptr)
av_cold int ff_libwebp_encode_init_common(AVCodecContext *avctx)
int av_frame_copy(AVFrame *dst, const AVFrame *src)
Copy the frame data from src to dst.
Definition: frame.c:792
#define FFMIN(a, b)
Definition: common.h:96
int width
picture width / height.
Definition: avcodec.h:1738
uint8_t w
Definition: llviddspenc.c:38
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:540
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:368
int ff_libwebp_error_to_averror(int err)
int compression_level
Definition: avcodec.h:1637
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
#define xs(width, name, var, subs,...)
Definition: cbs_vp9.c:354
main external API structure.
Definition: avcodec.h:1565
#define AV_PIX_FMT_RGB32
Definition: pixfmt.h:360
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
Definition: frame.c:324
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1631
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
void * priv_data
Definition: avcodec.h:1592
static av_always_inline int diff(const uint32_t a, const uint32_t b)
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:227
int height
Definition: frame.h:353
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:58