| /* |
| * Copyright 2020 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| // This program converts an image from stdin (e.g. a JPEG, PNG, etc.) to stdout |
| // (in the NIA/NIE format, a trivial image file format). |
| // |
| // The NIA/NIE file format specification is at: |
| // https://github.com/google/wuffs/blob/master/doc/spec/nie-spec.md |
| // |
| // Pass "-1" or "-first-frame-only" as a command line flag to output NIE (a |
| // still image) instead of NIA (an animated image). The output format (NIA or |
| // NIE) depends only on this flag's absence or presence, not on the stdin |
| // image's format. |
| // |
| // There are multiple codec implementations of any given image format. For |
| // example, as of May 2020, Chromium, Skia and Wuffs each have their own BMP |
| // decoder implementation. There is no standard "libbmp" that they all share. |
| // Comparing this program's output (or hashed output) to similar programs in |
| // other repositories can identify image inputs for which these decoders (or |
| // different versions of the same decoder) produce different output (pixels). |
| // |
| // An equivalent program (using the Chromium image codecs) is at: |
| // https://crrev.com/c/2210331 |
| // |
| // An equivalent program (using the Wuffs image codecs) is at: |
| // https://github.com/google/wuffs/blob/master/example/convert-to-nia/convert-to-nia.c |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include "include/codec/SkCodec.h" |
| #include "include/core/SkBitmap.h" |
| #include "include/core/SkData.h" |
| #include "src/base/SkAutoMalloc.h" |
| |
| static inline void set_u32le(uint8_t* ptr, uint32_t val) { |
| ptr[0] = val >> 0; |
| ptr[1] = val >> 8; |
| ptr[2] = val >> 16; |
| ptr[3] = val >> 24; |
| } |
| |
| static inline void set_u64le(uint8_t* ptr, uint64_t val) { |
| ptr[0] = val >> 0; |
| ptr[1] = val >> 8; |
| ptr[2] = val >> 16; |
| ptr[3] = val >> 24; |
| ptr[4] = val >> 32; |
| ptr[5] = val >> 40; |
| ptr[6] = val >> 48; |
| ptr[7] = val >> 56; |
| } |
| |
| static void write_nix_header(uint32_t magicU32le, uint32_t width, uint32_t height) { |
| uint8_t data[16]; |
| set_u32le(data + 0, magicU32le); |
| set_u32le(data + 4, 0x346E62FF); // 4 bytes per pixel non-premul BGRA. |
| set_u32le(data + 8, width); |
| set_u32le(data + 12, height); |
| fwrite(data, 1, 16, stdout); |
| } |
| |
| static bool write_nia_duration(uint64_t totalDurationMillis) { |
| // Flicks are NIA's unit of time. One flick (frame-tick) is 1 / 705_600_000 |
| // of a second. See https://github.com/OculusVR/Flicks |
| static constexpr uint64_t flicksPerMilli = 705600; |
| if (totalDurationMillis > (INT64_MAX / flicksPerMilli)) { |
| // Converting from millis to flicks would overflow. |
| return false; |
| } |
| |
| uint8_t data[8]; |
| set_u64le(data + 0, totalDurationMillis * flicksPerMilli); |
| fwrite(data, 1, 8, stdout); |
| return true; |
| } |
| |
| static void write_nie_pixels(uint32_t width, uint32_t height, const SkBitmap& bm) { |
| static constexpr size_t kBufferSize = 4096; |
| uint8_t buf[kBufferSize]; |
| size_t n = 0; |
| for (uint32_t y = 0; y < height; y++) { |
| for (uint32_t x = 0; x < width; x++) { |
| SkColor c = bm.getColor(x, y); |
| buf[n++] = SkColorGetB(c); |
| buf[n++] = SkColorGetG(c); |
| buf[n++] = SkColorGetR(c); |
| buf[n++] = SkColorGetA(c); |
| if (n == kBufferSize) { |
| fwrite(buf, 1, n, stdout); |
| n = 0; |
| } |
| } |
| } |
| if (n > 0) { |
| fwrite(buf, 1, n, stdout); |
| } |
| } |
| |
| static void write_nia_padding(uint32_t width, uint32_t height) { |
| // 4 bytes of padding when the width and height are both odd. |
| if (width & height & 1) { |
| uint8_t data[4]; |
| set_u32le(data + 0, 0); |
| fwrite(data, 1, 4, stdout); |
| } |
| } |
| |
| static void write_nia_footer(int repetitionCount, bool stillImage) { |
| uint8_t data[8]; |
| if (stillImage || (repetitionCount == SkCodec::kRepetitionCountInfinite)) { |
| set_u32le(data + 0, 0); |
| } else { |
| // NIA's loop count and Skia's repetition count differ by one. See |
| // https://github.com/google/wuffs/blob/master/doc/spec/nie-spec.md#nii-footer |
| set_u32le(data + 0, 1 + repetitionCount); |
| } |
| set_u32le(data + 4, 0x80000000); |
| fwrite(data, 1, 8, stdout); |
| } |
| |
| int main(int argc, char** argv) { |
| bool firstFrameOnly = false; |
| for (int a = 1; a < argc; a++) { |
| if ((strcmp(argv[a], "-1") == 0) || (strcmp(argv[a], "-first-frame-only") == 0)) { |
| firstFrameOnly = true; |
| break; |
| } |
| } |
| |
| std::unique_ptr<SkCodec> codec(SkCodec::MakeFromData(SkData::MakeFromFILE(stdin))); |
| if (!codec) { |
| SkDebugf("Decode failed.\n"); |
| return 1; |
| } |
| codec->getInfo().makeColorSpace(nullptr); |
| SkBitmap bm; |
| bm.allocPixels(codec->getInfo()); |
| size_t bmByteSize = bm.computeByteSize(); |
| |
| // Cache a frame that future frames may depend on. |
| int cachedFrame = SkCodec::kNoFrame; |
| SkAutoMalloc cachedFramePixels; |
| |
| uint64_t totalDurationMillis = 0; |
| const int frameCount = codec->getFrameCount(); |
| if (frameCount == 0) { |
| SkDebugf("No frames.\n"); |
| return 1; |
| } |
| std::vector<SkCodec::FrameInfo> frameInfos = codec->getFrameInfo(); |
| bool stillImage = frameInfos.size() <= 1; |
| |
| for (int i = 0; i < frameCount; i++) { |
| SkCodec::Options opts; |
| opts.fFrameIndex = i; |
| |
| if (!stillImage) { |
| int durationMillis = frameInfos[i].fDuration; |
| if (durationMillis < 0) { |
| SkDebugf("Negative animation duration.\n"); |
| return 1; |
| } |
| totalDurationMillis += static_cast<uint64_t>(durationMillis); |
| if (totalDurationMillis > INT64_MAX) { |
| SkDebugf("Unsupported animation duration.\n"); |
| return 1; |
| } |
| |
| if ((cachedFrame != SkCodec::kNoFrame) && |
| (cachedFrame == frameInfos[i].fRequiredFrame) && cachedFramePixels.get()) { |
| opts.fPriorFrame = cachedFrame; |
| memcpy(bm.getPixels(), cachedFramePixels.get(), bmByteSize); |
| } |
| } |
| |
| if (!firstFrameOnly) { |
| if (i == 0) { |
| write_nix_header(0x41AFC36E, // "nïA" magic string as a u32le. |
| bm.width(), bm.height()); |
| } |
| |
| if (!write_nia_duration(totalDurationMillis)) { |
| SkDebugf("Unsupported animation duration.\n"); |
| return 1; |
| } |
| } |
| |
| const SkCodec::Result result = |
| codec->getPixels(codec->getInfo(), bm.getPixels(), bm.rowBytes(), &opts); |
| if ((result != SkCodec::kSuccess) && (result != SkCodec::kIncompleteInput)) { |
| SkDebugf("Decode frame pixels #%d failed.\n", i); |
| return 1; |
| } |
| |
| // If the next frame depends on this one, store it in cachedFrame. It |
| // is possible that we may discard a frame that future frames depend |
| // on, but the codec will simply redecode the discarded frame. |
| if ((static_cast<size_t>(i + 1) < frameInfos.size()) && |
| (frameInfos[i + 1].fRequiredFrame == i)) { |
| cachedFrame = i; |
| memcpy(cachedFramePixels.reset(bmByteSize), bm.getPixels(), bmByteSize); |
| } |
| |
| int width = bm.width(); |
| int height = bm.height(); |
| write_nix_header(0x45AFC36E, // "nïE" magic string as a u32le. |
| width, height); |
| write_nie_pixels(width, height, bm); |
| if (result == SkCodec::kIncompleteInput) { |
| SkDebugf("Incomplete input.\n"); |
| return 1; |
| } |
| if (firstFrameOnly) { |
| return 0; |
| } |
| write_nia_padding(width, height); |
| } |
| write_nia_footer(codec->getRepetitionCount(), stillImage); |
| return 0; |
| } |