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1 /* | 1 /* |
2 * Copyright 2015 Google Inc. | 2 * Copyright 2015 Google Inc. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 | 7 |
8 #include "SkCodecPriv.h" | 8 #include "SkCodecPriv.h" |
9 #include "SkWebpCodec.h" | 9 #include "SkWebpCodec.h" |
10 #include "SkTemplates.h" | 10 #include "SkTemplates.h" |
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24 // WEBP starts with the following: | 24 // WEBP starts with the following: |
25 // RIFFXXXXWEBPVP | 25 // RIFFXXXXWEBPVP |
26 // Where XXXX is unspecified. | 26 // Where XXXX is unspecified. |
27 const char* bytes = static_cast<const char*>(buf); | 27 const char* bytes = static_cast<const char*>(buf); |
28 return bytesRead >= 14 && !memcmp(bytes, "RIFF", 4) && !memcmp(&bytes[8], "W
EBPVP", 6); | 28 return bytesRead >= 14 && !memcmp(bytes, "RIFF", 4) && !memcmp(&bytes[8], "W
EBPVP", 6); |
29 } | 29 } |
30 | 30 |
31 // Parse headers of RIFF container, and check for valid Webp (VP8) content. | 31 // Parse headers of RIFF container, and check for valid Webp (VP8) content. |
32 // NOTE: This calls peek instead of read, since onGetPixels will need these | 32 // NOTE: This calls peek instead of read, since onGetPixels will need these |
33 // bytes again. | 33 // bytes again. |
34 static bool webp_parse_header(SkStream* stream, int* width, int* height, SkEncod
edInfo* info) { | 34 static bool webp_parse_header(SkStream* stream, SkImageInfo* info) { |
35 unsigned char buffer[WEBP_VP8_HEADER_SIZE]; | 35 unsigned char buffer[WEBP_VP8_HEADER_SIZE]; |
36 SkASSERT(WEBP_VP8_HEADER_SIZE <= SkCodec::MinBufferedBytesNeeded()); | 36 SkASSERT(WEBP_VP8_HEADER_SIZE <= SkCodec::MinBufferedBytesNeeded()); |
37 | 37 |
38 const size_t bytesPeeked = stream->peek(buffer, WEBP_VP8_HEADER_SIZE); | 38 const size_t bytesPeeked = stream->peek(buffer, WEBP_VP8_HEADER_SIZE); |
39 if (bytesPeeked != WEBP_VP8_HEADER_SIZE) { | 39 if (bytesPeeked != WEBP_VP8_HEADER_SIZE) { |
40 // Use read + rewind as a backup | 40 // Use read + rewind as a backup |
41 if (stream->read(buffer, WEBP_VP8_HEADER_SIZE) != WEBP_VP8_HEADER_SIZE | 41 if (stream->read(buffer, WEBP_VP8_HEADER_SIZE) != WEBP_VP8_HEADER_SIZE |
42 || !stream->rewind()) | 42 || !stream->rewind()) |
43 return false; | 43 return false; |
44 } | 44 } |
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55 if (!sk_64_isS32(size)) { | 55 if (!sk_64_isS32(size)) { |
56 return false; | 56 return false; |
57 } | 57 } |
58 // now check that if we are 4-bytes per pixel, we also don't overflow | 58 // now check that if we are 4-bytes per pixel, we also don't overflow |
59 if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) { | 59 if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) { |
60 return false; | 60 return false; |
61 } | 61 } |
62 } | 62 } |
63 | 63 |
64 if (info) { | 64 if (info) { |
65 SkEncodedInfo::Color color; | 65 // FIXME: Is N32 the right type? |
66 SkEncodedInfo::Alpha alpha; | 66 // Is unpremul the right type? Clients of SkCodec may assume it's the |
67 switch (features.format) { | 67 // best type, when Skia currently cannot draw unpremul (and raster is fa
ster |
68 case 0: | 68 // with premul). |
69 // This indicates a "mixed" format. We would see this for | 69 *info = SkImageInfo::Make(features.width, features.height, kN32_SkColorT
ype, |
70 // animated webps or for webps encoded in multiple fragments. | 70 SkToBool(features.has_alpha) ? kUnpremul_SkAlp
haType |
71 // I believe that this is a rare case. | 71 : kOpaque_SkAlphaT
ype); |
72 // We could also guess kYUV here, but I think it makes more | |
73 // sense to guess kBGRA which is likely closer to the final | |
74 // output. Otherwise, we might end up converting | |
75 // BGRA->YUVA->BGRA. | |
76 color = SkEncodedInfo::kBGRA_Color; | |
77 alpha = SkEncodedInfo::kUnpremul_Alpha; | |
78 break; | |
79 case 1: | |
80 // This is the lossy format (YUV). | |
81 if (SkToBool(features.has_alpha)) { | |
82 color = SkEncodedInfo::kYUVA_Color; | |
83 alpha = SkEncodedInfo::kUnpremul_Alpha; | |
84 } else { | |
85 color = SkEncodedInfo::kYUV_Color; | |
86 alpha = SkEncodedInfo::kOpaque_Alpha; | |
87 } | |
88 break; | |
89 case 2: | |
90 // This is the lossless format (BGRA). | |
91 // FIXME: Should we check the has_alpha flag here? It looks | |
92 // like the image is encoded with an alpha channel | |
93 // regardless of whether or not the alpha flag is set. | |
94 color = SkEncodedInfo::kBGRA_Color; | |
95 alpha = SkEncodedInfo::kUnpremul_Alpha; | |
96 break; | |
97 default: | |
98 return false; | |
99 } | |
100 | |
101 *width = features.width; | |
102 *height = features.height; | |
103 *info = SkEncodedInfo::Make(color, alpha, 8); | |
104 } | 72 } |
105 return true; | 73 return true; |
106 } | 74 } |
107 | 75 |
108 SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) { | 76 SkCodec* SkWebpCodec::NewFromStream(SkStream* stream) { |
109 SkAutoTDelete<SkStream> streamDeleter(stream); | 77 SkAutoTDelete<SkStream> streamDeleter(stream); |
110 int width, height; | 78 SkImageInfo info; |
111 SkEncodedInfo info; | 79 if (webp_parse_header(stream, &info)) { |
112 if (webp_parse_header(stream, &width, &height, &info)) { | 80 return new SkWebpCodec(info, streamDeleter.release()); |
113 return new SkWebpCodec(width, height, info, streamDeleter.release()); | |
114 } | 81 } |
115 return nullptr; | 82 return nullptr; |
116 } | 83 } |
117 | 84 |
118 // This version is slightly different from SkCodecPriv's version of conversion_p
ossible. It | 85 // This version is slightly different from SkCodecPriv's version of conversion_p
ossible. It |
119 // supports both byte orders for 8888. | 86 // supports both byte orders for 8888. |
120 static bool webp_conversion_possible(const SkImageInfo& dst, const SkImageInfo&
src) { | 87 static bool webp_conversion_possible(const SkImageInfo& dst, const SkImageInfo&
src) { |
121 // FIXME: skbug.com/4895 | 88 // FIXME: skbug.com/4895 |
122 // Currently, we ignore the SkColorProfileType on the SkImageInfo. We | 89 // Currently, we ignore the SkColorProfileType on the SkImageInfo. We |
123 // will treat the encoded data as linear regardless of what the client | 90 // will treat the encoded data as linear regardless of what the client |
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278 return kSuccess; | 245 return kSuccess; |
279 case VP8_STATUS_SUSPENDED: | 246 case VP8_STATUS_SUSPENDED: |
280 // Break out of the switch statement. Continue the loop. | 247 // Break out of the switch statement. Continue the loop. |
281 break; | 248 break; |
282 default: | 249 default: |
283 return kInvalidInput; | 250 return kInvalidInput; |
284 } | 251 } |
285 } | 252 } |
286 } | 253 } |
287 | 254 |
288 SkWebpCodec::SkWebpCodec(int width, int height, const SkEncodedInfo& info, SkStr
eam* stream) | 255 SkWebpCodec::SkWebpCodec(const SkImageInfo& info, SkStream* stream) |
289 // The spec says an unmarked image is sRGB, so we return that space here. | 256 // The spec says an unmarked image is sRGB, so we return that space here. |
290 // TODO: Add support for parsing ICC profiles from webps. | 257 // TODO: Add support for parsing ICC profiles from webps. |
291 : INHERITED(width, height, info, stream, SkColorSpace::NewNamed(SkColorSpace
::kSRGB_Named)) {} | 258 : INHERITED(info, stream, SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named))
{} |
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