FFmpeg: libavcodec/libwebpenc.c Source File

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libavcodec

libwebpenc.c

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1 /*

2 * WebP encoding support via libwebp

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 */

22 /**

23 * @file

24 * WebP encoder using libwebp

25 */

27 #include <webp/encode.h>

29 #include "libavutil/common.h"

30 #include "libavutil/frame.h"

31 #include "libavutil/imgutils.h"

32 #include "libavutil/opt.h"

33 #include "avcodec.h"

34 #include "internal.h"

36 typedef struct LibWebPContext {

37 AVClass *class; // class for AVOptions

38 float quality; // lossy quality 0 - 100

39 int lossless; // use lossless encoding

40 int preset; // configuration preset

41 int chroma_warning; // chroma linesize mismatch warning has been printed

42 int conversion_warning; // pixel format conversion warning has been printed

43 WebPConfig config; // libwebp configuration

44 AVFrame *ref;

45 int cr_size;

46 int cr_threshold;

47 } LibWebPContext;

49 static int libwebp_error_to_averror(int err)

50 {

51 switch (err) {

52 case VP8_ENC_ERROR_OUT_OF_MEMORY:

53 case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:

54 return AVERROR(ENOMEM);

55 case VP8_ENC_ERROR_NULL_PARAMETER:

56 case VP8_ENC_ERROR_INVALID_CONFIGURATION:

57 case VP8_ENC_ERROR_BAD_DIMENSION:

58 return AVERROR(EINVAL);

59 }

60 return AVERROR_UNKNOWN;

61 }

63 static av_cold int libwebp_encode_init(AVCodecContext *avctx)

64 {

65 LibWebPContext *s = avctx->priv_data;

66 int ret;

68 if (avctx->global_quality >= 0)

69 s->quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA,

70 0.0f, 100.0f);

72 if (avctx->compression_level < 0 || avctx->compression_level > 6) {

73 av_log(avctx, AV_LOG_WARNING, "invalid compression level: %d\n",

74 avctx->compression_level);

75 avctx->compression_level = av_clip(avctx->compression_level, 0, 6);

76 }

78 if (s->preset >= WEBP_PRESET_DEFAULT) {

79 ret = WebPConfigPreset(&s->config, s->preset, s->quality);

80 if (!ret)

81 return AVERROR_UNKNOWN;

82 s->lossless = s->config.lossless;

83 s->quality = s->config.quality;

84 avctx->compression_level = s->config.method;

85 } else {

86 ret = WebPConfigInit(&s->config);

87 if (!ret)

88 return AVERROR_UNKNOWN;

90 s->config.lossless = s->lossless;

91 s->config.quality = s->quality;

92 s->config.method = avctx->compression_level;

94 ret = WebPValidateConfig(&s->config);

95 if (!ret)

96 return AVERROR(EINVAL);

97 }

99 av_log(avctx, AV_LOG_DEBUG, "%s - quality=%.1f method=%d\n",

100 s->lossless ? "Lossless" : "Lossy", s->quality,

101 avctx->compression_level);

102

103 return 0;

104 }

105

106 static int libwebp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,

107 const AVFrame *frame, int *got_packet)

108 {

109 LibWebPContext *s = avctx->priv_data;

110 AVFrame *alt_frame = NULL;

111 WebPPicture *pic = NULL;

112 WebPMemoryWriter mw = { 0 };

113 int ret;

114

115 if (avctx->width > WEBP_MAX_DIMENSION || avctx->height > WEBP_MAX_DIMENSION) {

116 av_log(avctx, AV_LOG_ERROR, "Picture size is too large. Max is %dx%d.\n",

117 WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);

118 return AVERROR(EINVAL);

119 }

120

121 pic = av_malloc(sizeof(*pic));

122 if (!pic)

123 return AVERROR(ENOMEM);

124

125 ret = WebPPictureInit(pic);

126 if (!ret) {

127 ret = AVERROR_UNKNOWN;

128 goto end;

129 }

130 pic->width = avctx->width;

131 pic->height = avctx->height;

132

133 if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {

134 if (!s->lossless) {

135 /* libwebp will automatically convert RGB input to YUV when

136 encoding lossy. */

137 if (!s->conversion_warning) {

138 av_log(avctx, AV_LOG_WARNING,

139 "Using libwebp for RGB-to-YUV conversion. You may want "

140 "to consider passing in YUV instead for lossy "

141 "encoding.\n");

142 s->conversion_warning = 1;

143 }

144 }

145 pic->use_argb = 1;

146 pic->argb = (uint32_t *)frame->data[0];

147 pic->argb_stride = frame->linesize[0] / 4;

148 } else {

149 if (frame->linesize[1] != frame->linesize[2] || s->cr_threshold) {

150 if (!s->chroma_warning && !s->cr_threshold) {

151 av_log(avctx, AV_LOG_WARNING,

152 "Copying frame due to differing chroma linesizes.\n");

153 s->chroma_warning = 1;

154 }

155 alt_frame = av_frame_alloc();

156 if (!alt_frame) {

157 ret = AVERROR(ENOMEM);

158 goto end;

159 }

160 alt_frame->width = frame->width;

161 alt_frame->height = frame->height;

162 alt_frame->format = frame->format;

163 if (s->cr_threshold)

164 alt_frame->format = AV_PIX_FMT_YUVA420P;

165 ret = av_frame_get_buffer(alt_frame, 32);

166 if (ret < 0)

167 goto end;

168 alt_frame->format = frame->format;

169 av_frame_copy(alt_frame, frame);

170 frame = alt_frame;

171 if (s->cr_threshold) {

172 int x,y, x2, y2, p;

173 int bs = s->cr_size;

174

175 if (!s->ref) {

176 s->ref = av_frame_clone(frame);

177 if (!s->ref) {

178 ret = AVERROR(ENOMEM);

179 goto end;

180 }

181 }

182

183 alt_frame->format = AV_PIX_FMT_YUVA420P;

184 for (y = 0; y < frame->height; y+= bs) {

185 for (x = 0; x < frame->width; x+= bs) {

186 int skip;

187 int sse = 0;

188 for (p = 0; p < 3; p++) {

189 int bs2 = bs >> !!p;

190 int w = FF_CEIL_RSHIFT(frame->width , !!p);

191 int h = FF_CEIL_RSHIFT(frame->height, !!p);

192 int xs = x >> !!p;

193 int ys = y >> !!p;

194 for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {

195 for (x2 = xs; x2 < FFMIN(xs + bs2, w); x2++) {

196 int diff = frame->data[p][frame->linesize[p] * y2 + x2]

197 -s->ref->data[p][frame->linesize[p] * y2 + x2];

198 sse += diff*diff;

199 }

200 }

201 }

202 skip = sse < s->cr_threshold && frame->data[3] != s->ref->data[3];

203 if (!skip)

204 for (p = 0; p < 3; p++) {

205 int bs2 = bs >> !!p;

206 int w = FF_CEIL_RSHIFT(frame->width , !!p);

207 int h = FF_CEIL_RSHIFT(frame->height, !!p);

208 int xs = x >> !!p;

209 int ys = y >> !!p;

210 for (y2 = ys; y2 < FFMIN(ys + bs2, h); y2++) {

211 memcpy(&s->ref->data[p][frame->linesize[p] * y2 + xs],

212 & frame->data[p][frame->linesize[p] * y2 + xs], FFMIN(bs2, w-xs));

213 }

214 }

215 for (y2 = y; y2 < FFMIN(y+bs, frame->height); y2++) {

216 memset(&frame->data[3][frame->linesize[3] * y2 + x],

217 skip ? 0 : 255,

218 FFMIN(bs, frame->width-x));

219 }

220 }

221 }

222 }

223 }

224

225 pic->use_argb = 0;

226 pic->y = frame->data[0];

227 pic->u = frame->data[1];

228 pic->v = frame->data[2];

229 pic->y_stride = frame->linesize[0];

230 pic->uv_stride = frame->linesize[1];

231 if (frame->format == AV_PIX_FMT_YUVA420P) {

232 pic->colorspace = WEBP_YUV420A;

233 pic->a = frame->data[3];

234 pic->a_stride = frame->linesize[3];

235 if (alt_frame)

236 WebPCleanupTransparentArea(pic);

237 } else {

238 pic->colorspace = WEBP_YUV420;

239 }

240

241 if (s->lossless) {

242 /* We do not have a way to automatically prioritize RGB over YUV

243 in automatic pixel format conversion based on whether we're

244 encoding lossless or lossy, so we do conversion with libwebp as

245 a convenience. */

246 if (!s->conversion_warning) {

247 av_log(avctx, AV_LOG_WARNING,

248 "Using libwebp for YUV-to-RGB conversion. You may want "

249 "to consider passing in RGB instead for lossless "

250 "encoding.\n");

251 s->conversion_warning = 1;

252 }

253

254 #if (WEBP_ENCODER_ABI_VERSION <= 0x201)

255 /* libwebp should do the conversion automatically, but there is a

256 bug that causes it to return an error instead, so a work-around

257 is required.

258 See https://code.google.com/p/webp/issues/detail?id=178 */

259 pic->memory_ = (void*)1; /* something non-null */

260 ret = WebPPictureYUVAToARGB(pic);

261 if (!ret) {

262 av_log(avctx, AV_LOG_ERROR,

263 "WebPPictureYUVAToARGB() failed with error: %d\n",

264 pic->error_code);

265 ret = libwebp_error_to_averror(pic->error_code);

266 goto end;

267 }

268 pic->memory_ = NULL; /* restore pointer */

269 #endif

270 }

271 }

272

273 WebPMemoryWriterInit(&mw);

274 pic->custom_ptr = &mw;

275 pic->writer = WebPMemoryWrite;

276

277 ret = WebPEncode(&s->config, pic);

278 if (!ret) {

279 av_log(avctx, AV_LOG_ERROR, "WebPEncode() failed with error: %d\n",

280 pic->error_code);

281 ret = libwebp_error_to_averror(pic->error_code);

282 goto end;

283 }

284

285 ret = ff_alloc_packet(pkt, mw.size);

286 if (ret < 0)

287 goto end;

288 memcpy(pkt->data, mw.mem, mw.size);

289

290 pkt->flags |= AV_PKT_FLAG_KEY;

291 *got_packet = 1;

292

293 end:

294 #if (WEBP_ENCODER_ABI_VERSION > 0x0203)

295 WebPMemoryWriterClear(&mw);

296 #else

297 free(mw.mem); /* must use free() according to libwebp documentation */

298 #endif

299 WebPPictureFree(pic);

300 av_freep(&pic);

301 av_frame_free(&alt_frame);

302

303 return ret;

304 }

305

306 static int libwebp_encode_close(AVCodecContext *avctx)

307 {

308 LibWebPContext *s = avctx->priv_data;

309

310 av_frame_free(&s->ref);

311

312 return 0;

313 }

314

315 #define OFFSET(x) offsetof(LibWebPContext, x)

316 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM

317 static const AVOption options[] = {

318 { "lossless", "Use lossless mode", OFFSET(lossless), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },

319 { "preset", "Configuration preset", OFFSET(preset), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, WEBP_PRESET_TEXT, VE, "preset" },

320 { "none", "do not use a preset", 0, AV_OPT_TYPE_CONST, { .i64 = -1 }, 0, 0, VE, "preset" },

321 { "default", "default preset", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DEFAULT }, 0, 0, VE, "preset" },

322 { "picture", "digital picture, like portrait, inner shot", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PICTURE }, 0, 0, VE, "preset" },

323 { "photo", "outdoor photograph, with natural lighting", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PHOTO }, 0, 0, VE, "preset" },

324 { "drawing", "hand or line drawing, with high-contrast details", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DRAWING }, 0, 0, VE, "preset" },

325 { "icon", "small-sized colorful images", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_ICON }, 0, 0, VE, "preset" },

326 { "text", "text-like", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_TEXT }, 0, 0, VE, "preset" },

327 { "cr_threshold","Conditional replenishment threshold", OFFSET(cr_threshold), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE },

328 { "cr_size" ,"Conditional replenishment block size", OFFSET(cr_size) , AV_OPT_TYPE_INT, { .i64 = 16 }, 0, 256, VE },

329 { "quality" ,"Quality", OFFSET(quality), AV_OPT_TYPE_FLOAT, { .dbl = 75 }, 0, 100, VE },

330 { NULL },

331 };

332

333

334 static const AVClass class = {

335 .class_name = "libwebp",

336 .item_name = av_default_item_name,

337 .option = options,

338 .version = LIBAVUTIL_VERSION_INT,

339 };

340

341 static const AVCodecDefault libwebp_defaults[] = {

342 { "compression_level", "4" },

343 { "global_quality", "-1" },

344 { NULL },

345 };

346

347 AVCodec ff_libwebp_encoder = {

348 .name = "libwebp",

349 .long_name = NULL_IF_CONFIG_SMALL("libwebp WebP image"),

350 .type = AVMEDIA_TYPE_VIDEO,

351 .id = AV_CODEC_ID_WEBP,

352 .priv_data_size = sizeof(LibWebPContext),

353 .init = libwebp_encode_init,

354 .encode2 = libwebp_encode_frame,

355 .close = libwebp_encode_close,

356 .pix_fmts = (const enum AVPixelFormat[]) {

357 AV_PIX_FMT_RGB32,

358 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,

359 AV_PIX_FMT_NONE

360 },

361 .priv_class = &class,

362 .defaults = libwebp_defaults,

363 };

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