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 } LibWebPContext;

46 static int libwebp_error_to_averror(int err)

47 {

48 switch (err) {

49 case VP8_ENC_ERROR_OUT_OF_MEMORY:

50 case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:

51 return AVERROR(ENOMEM);

52 case VP8_ENC_ERROR_NULL_PARAMETER:

53 case VP8_ENC_ERROR_INVALID_CONFIGURATION:

54 case VP8_ENC_ERROR_BAD_DIMENSION:

55 return AVERROR(EINVAL);

56 }

57 return AVERROR_UNKNOWN;

58 }

60 static av_cold int libwebp_encode_init(AVCodecContext *avctx)

61 {

62 LibWebPContext *s = avctx->priv_data;

63 int ret;

65 if (avctx->global_quality < 0)

66 avctx->global_quality = 75 * FF_QP2LAMBDA;

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

68 0.0f, 100.0f);

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

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

72 avctx->compression_level);

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

74 }

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

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

78 if (!ret)

79 return AVERROR_UNKNOWN;

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

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

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

83 } else {

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

85 if (!ret)

86 return AVERROR_UNKNOWN;

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

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

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

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

93 if (!ret)

94 return AVERROR(EINVAL);

95 }

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

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

99 avctx->compression_level);

100

101 return 0;

102 }

103

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

105 const AVFrame *frame, int *got_packet)

106 {

107 LibWebPContext *s = avctx->priv_data;

108 AVFrame *alt_frame = NULL;

109 WebPPicture *pic = NULL;

110 WebPMemoryWriter mw = { 0 };

111 int ret;

112

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

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

115 WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);

116 return AVERROR(EINVAL);

117 }

118

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

120 if (!pic)

121 return AVERROR(ENOMEM);

122

123 ret = WebPPictureInit(pic);

124 if (!ret) {

125 ret = AVERROR_UNKNOWN;

126 goto end;

127 }

128 pic->width = avctx->width;

129 pic->height = avctx->height;

130

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

132 if (!s->lossless) {

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

134 encoding lossy. */

135 if (!s->conversion_warning) {

136 av_log(avctx, AV_LOG_WARNING,

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

138 "to consider passing in YUV instead for lossy "

139 "encoding.\n");

140 s->conversion_warning = 1;

141 }

142 }

143 pic->use_argb = 1;

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

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

146 } else {

147 if (frame->linesize[1] != frame->linesize[2]) {

148 if (!s->chroma_warning) {

149 av_log(avctx, AV_LOG_WARNING,

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

151 s->chroma_warning = 1;

152 }

153 alt_frame = av_frame_alloc();

154 if (!alt_frame) {

155 ret = AVERROR(ENOMEM);

156 goto end;

157 }

158 alt_frame->width = frame->width;

159 alt_frame->height = frame->height;

160 alt_frame->format = frame->format;

161 ret = av_frame_get_buffer(alt_frame, 32);

162 if (ret < 0)

163 goto end;

164 av_frame_copy(alt_frame, frame);

165 frame = alt_frame;

166 }

167 pic->use_argb = 0;

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

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

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

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

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

173 if (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) {

174 pic->colorspace = WEBP_YUV420A;

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

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

177 } else {

178 pic->colorspace = WEBP_YUV420;

179 }

180

181 if (s->lossless) {

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

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

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

185 a convenience. */

186 if (!s->conversion_warning) {

187 av_log(avctx, AV_LOG_WARNING,

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

189 "to consider passing in RGB instead for lossless "

190 "encoding.\n");

191 s->conversion_warning = 1;

192 }

193

194 #if (WEBP_ENCODER_ABI_VERSION <= 0x201)

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

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

197 is required.

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

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

200 ret = WebPPictureYUVAToARGB(pic);

201 if (!ret) {

202 av_log(avctx, AV_LOG_ERROR,

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

204 pic->error_code);

205 ret = libwebp_error_to_averror(pic->error_code);

206 goto end;

207 }

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

209 #endif

210 }

211 }

212

213 WebPMemoryWriterInit(&mw);

214 pic->custom_ptr = &mw;

215 pic->writer = WebPMemoryWrite;

216

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

218 if (!ret) {

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

220 pic->error_code);

221 ret = libwebp_error_to_averror(pic->error_code);

222 goto end;

223 }

224

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

226 if (ret < 0)

227 goto end;

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

229

230 pkt->flags |= AV_PKT_FLAG_KEY;

231 *got_packet = 1;

232

233 end:

234 #if (WEBP_ENCODER_ABI_VERSION > 0x0203)

235 WebPMemoryWriterClear(&mw);

236 #else

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

238 #endif

239 WebPPictureFree(pic);

240 av_freep(&pic);

241 av_frame_free(&alt_frame);

242

243 return ret;

244 }

245

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

247 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM

248 static const AVOption options[] = {

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

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

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

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

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

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

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

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

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

258 { NULL },

259 };

260

261 static const AVClass class = {

262 .class_name = "libwebp",

263 .item_name = av_default_item_name,

264 .option = options,

265 .version = LIBAVUTIL_VERSION_INT,

266 };

267

268 static const AVCodecDefault libwebp_defaults[] = {

269 { "compression_level", "4" },

270 { "global_quality", "-1" },

271 { NULL },

272 };

273

274 AVCodec ff_libwebp_encoder = {

275 .name = "libwebp",

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

277 .type = AVMEDIA_TYPE_VIDEO,

278 .id = AV_CODEC_ID_WEBP,

279 .priv_data_size = sizeof(LibWebPContext),

280 .init = libwebp_encode_init,

281 .encode2 = libwebp_encode_frame,

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

283 AV_PIX_FMT_RGB32,

284 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,

285 AV_PIX_FMT_NONE

286 },

287 .priv_class = &class,

288 .defaults = libwebp_defaults,

289 };

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