Image (Logo): uses native image decoder on Android

Codec (Android): uses `availability` feature test
2026-10-28 07:44:06 +01:00 · 2026-09-18 01:10:18 +08:00
parent 97ac94eb44
commit 70d2dd37a6
7 changed files with 480 additions and 42 deletions
@@ -0,0 +1,397 @@
+
+#include "image.h"
+#include "common/androidApi.h"
+#include "common/io.h"
+#include "common/mallocHelper.h"
+
+#include <android/bitmap.h>
+#include <android/imagedecoder.h>
+
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+
+static inline bool androidImageDecoderError(const char** error, const char* message) {
+    if (error) {
+        *error = message;
+    }
+    return false;
+}
+
+// AImageDecoder decodes to premultiplied alpha, and it can not be asked for straight alpha once a
+// target size is in effect: AImageDecoder_setUnpremultipliedRequired fails with
+// ANDROID_IMAGE_DECODER_INVALID_CONVERSION, documented as "Unpremultiplied is not possible due to
+// an existing scale set by AImageDecoder_setTargetSize". Premultiplied is the right domain to
+// scale in anyway -- interpolating straight alpha averages the colour of fully transparent pixels
+// into the edges next to them, which shows up as dark fringes -- so the decoder is left alone and
+// this runs afterwards, exactly as the ImageIO backend does.
+static void unPremultiplyRGBA(uint8_t* data, size_t pixelCount) {
+    for (size_t i = 0; i < pixelCount; ++i) {
+        uint8_t* const p = data + i * 4;
+        const uint8_t a = p[3];
+        if (a == 0) {
+            p[0] = p[1] = p[2] = 0;
+        } else if (a < 255) {
+            p[0] = (uint8_t) ((p[0] * 255 + a / 2) / a);
+            p[1] = (uint8_t) ((p[1] * 255 + a / 2) / a);
+            p[2] = (uint8_t) ((p[2] * 255 + a / 2) / a);
+        }
+    }
+}
+
+// Copy one decoded frame into a tightly packed, straight alpha buffer of its own.
+//
+// A copy rather than a hand-over: the animation path has to keep the decoder's own buffer intact,
+// because AImageDecoder blends each frame into the one that is already there. The still path only
+// needs the packed result, and going through here keeps the two identical.
+//
+// `premultiplied` is what the decoder reports about the pixels it produced, so a source that was
+// decoded straight is copied and nothing else.
+static uint8_t* androidPackFrame(const uint8_t* src, size_t stride, uint32_t width, uint32_t height, bool premultiplied) {
+    const size_t packedStride = (size_t) width * 4;
+    uint8_t* pixels = (uint8_t*) malloc(packedStride * height);
+    if (pixels == nullptr) {
+        return nullptr;
+    }
+
+    for (uint32_t y = 0; y < height; ++y) {
+        memcpy(pixels + (size_t) y * packedStride, src + (size_t) y * stride, packedStride);
+    }
+
+    if (premultiplied) {
+        unPremultiplyRGBA(pixels, (size_t) width * height);
+    }
+    return pixels;
+}
+
+// Everything the still and the animation path share: read the source size, resolve the requested
+// pixel size, ask for RGBA8888 and let the decoder do the scaling.
+FF_REQUIRES_API(30) static bool androidResolveDecoder(AImageDecoder* decoder, FFLogoRequestData* requestData, size_t* outStride, bool* outPremultiplied, const char** error) {
+    const AImageDecoderHeaderInfo* header = AImageDecoder_getHeaderInfo(decoder);
+    // Both are int32_t, and anything <= 0 is not a usable source
+    const int32_t sourceWidth = AImageDecoderHeaderInfo_getWidth(header);
+    const int32_t sourceHeight = AImageDecoderHeaderInfo_getHeight(header);
+    if (sourceWidth <= 0 || sourceHeight <= 0) {
+        return androidImageDecoderError(error, "invalid image dimensions");
+    }
+
+    // Fill in the missing dimension, keeping the source aspect ratio (same as the IM path)
+    uint32_t width = requestData->logoPixelWidth;
+    uint32_t height = requestData->logoPixelHeight;
+    if (width == 0 && height == 0) {
+        width = (uint32_t) sourceWidth;
+        height = (uint32_t) sourceHeight;
+    } else if (width == 0) {
+        width = (uint32_t) ((double) sourceWidth / (double) sourceHeight * height);
+    } else if (height == 0) {
+        height = (uint32_t) ((double) sourceHeight / (double) sourceWidth * width);
+    }
+    if (width == 0 || height == 0) {
+        return androidImageDecoderError(error, "invalid target dimensions");
+    }
+
+    if (AImageDecoder_setAndroidBitmapFormat(decoder, ANDROID_BITMAP_FORMAT_RGBA_8888) != ANDROID_IMAGE_DECODER_SUCCESS) {
+        return androidImageDecoderError(error, "failed to select the RGBA8888 output format");
+    }
+
+    // A source that is already the requested size needs no scaling at all, and leaving the target
+    // size unset buys one more thing: AImageDecoder refuses straight alpha only *because* of a
+    // scale, so unscaled output can be decoded straight and no conversion follows. That is also
+    // the more accurate of the two, having no integer rounding to recover from.
+    if (width == (uint32_t) sourceWidth && height == (uint32_t) sourceHeight) {
+        *outPremultiplied = AImageDecoder_setUnpremultipliedRequired(decoder, true) != ANDROID_IMAGE_DECODER_SUCCESS;
+    } else {
+        // Scaling is part of the decode: the decoder samples the source down (or up) as it goes, so
+        // there is neither a full-size intermediate nor a separate resize step.
+        if (AImageDecoder_setTargetSize(decoder, (int32_t) width, (int32_t) height) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "failed to scale the image");
+        }
+        *outPremultiplied = true;
+    }
+
+    const size_t stride = AImageDecoder_getMinimumStride(decoder);
+    if (stride < (size_t) width * 4 || stride > SIZE_MAX / height) {
+        return androidImageDecoderError(error, "invalid target dimensions");
+    }
+
+    requestData->logoPixelWidth = width;
+    requestData->logoPixelHeight = height;
+    *outStride = stride;
+    return true;
+}
+
+bool ffImageCreateAID(FFLogoRequestData* requestData, FFImageBuffer* out, const char** error) {
+    // AImageDecoder is API 30, and fastfetch still runs on devices below that, so this is a real
+    // run-time check and not a compile-time constant. See common/androidApi.h for why.
+    if (FF_API_AT_LEAST(30)) {
+        FF_AUTO_CLOSE_FD int fd = open(instance.config.logo.source.chars, O_RDONLY | O_CLOEXEC);
+        if (fd < 0) {
+            return androidImageDecoderError(error, "failed to open the image source");
+        }
+
+        AImageDecoder* decoder = nullptr;
+        if (AImageDecoder_createFromFd(fd, &decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "unsupported or unreadable image format");
+        }
+
+        size_t stride = 0;
+        bool premultiplied = true;
+        if (!androidResolveDecoder(decoder, requestData, &stride, &premultiplied, error)) {
+            AImageDecoder_delete(decoder);
+            return false;
+        }
+
+        const uint32_t width = requestData->logoPixelWidth;
+        const uint32_t height = requestData->logoPixelHeight;
+        const size_t packedStride = (size_t) width * 4;
+        const size_t bufferSize = stride * height;
+
+        FF_AUTO_FREE uint8_t* decoded = (uint8_t*) malloc(bufferSize);
+        if (decoded == nullptr) {
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+
+        const int result = AImageDecoder_decodeImage(decoder, decoded, stride, bufferSize);
+        // The decoder reads from the fd while decoding, so it outlives the decode but not the fd
+        AImageDecoder_delete(decoder);
+        if (result != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "failed to decode the image");
+        }
+
+        // Without row padding the decoder's buffer is already laid out the way the contract wants,
+        // so it is finished in place and handed over rather than copied.
+        if (stride == packedStride) {
+            if (premultiplied) {
+                unPremultiplyRGBA(decoded, (size_t) width * height);
+            }
+            out->data = decoded;
+            decoded = nullptr; // Ownership is transferred to `out`
+        } else {
+            out->data = androidPackFrame(decoded, stride, width, height, premultiplied);
+            if (out->data == nullptr) {
+                return androidImageDecoderError(error, "out of memory");
+            }
+        }
+
+        out->width = width;
+        out->height = height;
+        return true;
+    } else {
+        return androidImageDecoderError(error, "AImageDecoder requires Android 11 (API 30) or newer");
+    }
+}
+
+// ---------------------------------------------------------------------------------------------
+// Animation
+//
+// AImageDecoder composes the frames itself. Given the same buffer for every call, it decodes the
+// part of the canvas a frame actually covers and blends it over what is already there, and it
+// restores the buffer for a DISPOSE_OP_PREVIOUS frame on its own. So unlike the Windows backend,
+// there is no canvas to maintain here: the session keeps the decoder's buffer and hands out a copy
+// of it per frame.
+//
+// Two things follow from the decoder only ever walking forwards:
+//
+//  * The frame count and every gap have to be collected up front by advancing through the whole
+//    animation and rewinding, which is what the session contract asks for anyway -- a negative
+//    --logo-animation-frame has to be resolved before the first frame is taken.
+//  * Reaching a frame that is not the next one means rewinding and walking forward again, which is
+//    slower than refusing it but keeps the iterator usable after the last frame.
+//
+// The loop count is the one thing AImageDecoder does not expose: it has no API for it at any
+// level, so the animation is reported as looping forever, which is what an animated GIF with no
+// NETSCAPE block does in every viewer anyway.
+// ---------------------------------------------------------------------------------------------
+
+typedef struct FFAndroidAnimation {
+    AImageDecoder* decoder;
+    uint8_t* canvas; // the decoder's buffer; every frame is blended into what is already in it
+    size_t stride;
+    size_t size;
+    uint32_t width;
+    uint32_t height;
+    uint32_t nextIndex; // the frame the decoder is positioned on
+    bool premultiplied; // whether the decoder's frames need un-premultiplying
+    int32_t minGap;
+    int32_t* delaysCs; // one per frame, in centiseconds
+} FFAndroidAnimation;
+
+FF_REQUIRES_API(31) static bool androidAnimationGetFrame(FFImageAnimation* animation, uint32_t index, FFImageFrame* out, const char** error) {
+    FFAndroidAnimation* session = (FFAndroidAnimation*) ffImageAnimationGetImpl(animation);
+
+    // Frames come out of the decoder in order, so anything before the current one means starting
+    // over. AImageDecoder_rewind needs an animated source; it is reached here only once a frame
+    // has already been taken, which means the source is one.
+    if (index < session->nextIndex) {
+        if (AImageDecoder_rewind(session->decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "failed to rewind the animation");
+        }
+        session->nextIndex = 0;
+    }
+
+    // Skipped frames still have to be decoded: each frame is blended into the buffer that the
+    // following one builds on, so the buffer would be wrong without them.
+    while (session->nextIndex < index) {
+        if (AImageDecoder_decodeImage(session->decoder, session->canvas, session->stride, session->size) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "failed to decode an animation frame");
+        }
+        if (AImageDecoder_advanceFrame(session->decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "failed to advance to the next animation frame");
+        }
+        ++session->nextIndex;
+    }
+
+    if (AImageDecoder_decodeImage(session->decoder, session->canvas, session->stride, session->size) != ANDROID_IMAGE_DECODER_SUCCESS) {
+        return androidImageDecoderError(error, "failed to decode the animation frame");
+    }
+
+    uint8_t* frame = androidPackFrame(session->canvas, session->stride, session->width, session->height, session->premultiplied);
+    if (frame == nullptr) {
+        return androidImageDecoderError(error, "out of memory");
+    }
+
+    // Position on the following frame. Past the last one this reports FINISHED, which is expected
+    // and harmless: the frame just handed out is complete, and anything else the caller asks for
+    // restarts above.
+    AImageDecoder_advanceFrame(session->decoder);
+    ++session->nextIndex;
+
+    // The same mapping the ImageIO backend settled on: the raw gap is in centiseconds, a floor of
+    // 100 ms applies only when every frame is zero, and what is left at <= 0 means gapless.
+    const int32_t gap = (session->delaysCs[index] > session->minGap ? session->delaysCs[index] : session->minGap) * 10;
+    out->data = frame;
+    out->delayMs = gap > 0 ? gap : -1;
+    return true;
+}
+
+FF_REQUIRES_API(31) static void androidAnimationDestroy(FFImageAnimation* animation) {
+    FFAndroidAnimation* session = (FFAndroidAnimation*) ffImageAnimationGetImpl(animation);
+    if (session == nullptr) {
+        return;
+    }
+
+    AImageDecoder_delete(session->decoder);
+    free(session->canvas);
+    free(session->delaysCs);
+    free(session);
+}
+
+bool ffImageAnimationOpenAID(FFLogoRequestData* requestData, FFImageAnimation** out, const char** error) {
+    // Decoding past the first frame needs API 31: AImageDecoder_advanceFrame and
+    // AImageDecoderFrameInfo are both introduced there, and AImageDecoder_decodeImage only
+    // documents decoding "all of the frames" from that level on.
+    if (FF_API_AT_LEAST(31)) {
+        FF_AUTO_CLOSE_FD int fd = open(instance.config.logo.source.chars, O_RDONLY | O_CLOEXEC);
+        if (fd < 0) {
+            return androidImageDecoderError(error, "failed to open the image source");
+        }
+
+        AImageDecoder* decoder = nullptr;
+        if (AImageDecoder_createFromFd(fd, &decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            return androidImageDecoderError(error, "unsupported or unreadable image format");
+        }
+
+        size_t stride = 0;
+        bool premultiplied = true;
+        if (!androidResolveDecoder(decoder, requestData, &stride, &premultiplied, error)) {
+            AImageDecoder_delete(decoder);
+            return false;
+        }
+
+        AImageDecoderFrameInfo* frameInfo = AImageDecoderFrameInfo_create();
+        if (frameInfo == nullptr) {
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+
+        // Walk the animation once, recording every gap on the way, so that both the frame count
+        // and each frame's timing are known before the first frame is decoded.
+        uint32_t capacity = 16;
+        uint32_t frameCount = 0;
+        int32_t* delays = (int32_t*) malloc(capacity * sizeof(*delays));
+        if (delays == nullptr) {
+            AImageDecoderFrameInfo_delete(frameInfo);
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+
+        int32_t minGap = 10;
+        for (;;) {
+            if (frameCount == capacity) {
+                const uint32_t grown = capacity * 2;
+                int32_t* resized = (int32_t*) realloc(delays, grown * sizeof(*delays));
+                if (resized == nullptr) {
+                    free(delays);
+                    AImageDecoderFrameInfo_delete(frameInfo);
+                    AImageDecoder_delete(decoder);
+                    return androidImageDecoderError(error, "out of memory");
+                }
+                delays = resized;
+                capacity = grown;
+            }
+
+            int64_t nanos = 0;
+            if (AImageDecoder_getFrameInfo(decoder, frameInfo) == ANDROID_IMAGE_DECODER_SUCCESS) {
+                nanos = AImageDecoderFrameInfo_getDuration(frameInfo);
+            }
+            const int32_t cs = nanos > 0 ? (int32_t) (nanos / 10000000) : 0;
+            delays[frameCount++] = cs;
+            if (cs > 0) {
+                minGap = 0;
+            }
+
+            if (AImageDecoder_advanceFrame(decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+                break;
+            }
+        }
+        AImageDecoderFrameInfo_delete(frameInfo);
+
+        // A single frame source never advanced, so it is still positioned on its only frame and
+        // has nothing to rewind. Everything else stopped in the finished state.
+        if (frameCount > 1 && AImageDecoder_rewind(decoder) != ANDROID_IMAGE_DECODER_SUCCESS) {
+            free(delays);
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "failed to rewind the animation");
+        }
+
+        FFAndroidAnimation* session = (FFAndroidAnimation*) calloc(1, sizeof(*session));
+        if (session == nullptr) {
+            free(delays);
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+        session->decoder = decoder;
+        session->stride = stride;
+        session->size = stride * requestData->logoPixelHeight;
+        session->width = requestData->logoPixelWidth;
+        session->height = requestData->logoPixelHeight;
+        session->premultiplied = premultiplied;
+        session->minGap = minGap;
+        session->delaysCs = delays;
+
+        session->canvas = (uint8_t*) calloc(1, session->size);
+        if (session->canvas == nullptr) {
+            free(session->delaysCs);
+            free(session);
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+
+        // 0: AImageDecoder has no API for the loop count, and looping forever is what a viewer
+        // does with an animation that does not declare one.
+        FFImageAnimation* animation = ffImageAnimationCreate(frameCount, 0, session, androidAnimationGetFrame, androidAnimationDestroy);
+        if (animation == nullptr) {
+            free(session->canvas);
+            free(session->delaysCs);
+            free(session);
+            AImageDecoder_delete(decoder);
+            return androidImageDecoderError(error, "out of memory");
+        }
+
+        *out = animation;
+        return true;
+    } else {
+        return androidImageDecoderError(error, "animation support requires Android 12 (API 31) or newer");
+    }
+}
@@ -447,7 +447,7 @@ static bool printImageKittyDirect(bool printError) {
    return true;
 }

-#if defined(FF_HAVE_IMAGEMAGICK7) || defined(FF_HAVE_IMAGEMAGICK6) || defined(_WIN32) || defined(__APPLE__) || defined(FF_HAVE_SIXEL)
+#if defined(FF_HAVE_IMAGEMAGICK7) || defined(FF_HAVE_IMAGEMAGICK6) || defined(_WIN32) || defined(__APPLE__) || defined(__ANDROID__) || defined(FF_HAVE_SIXEL)

    #define FF_KITTY_MAX_CHUNK_SIZE 4096

@@ -807,6 +807,8 @@ bool ffImageCreate(FFLogoRequestData* requestData, FFImageBuffer* out, const cha
    return ffImageCreateWIC(requestData, out, error);
    #elif defined(__APPLE__)
    return ffImageCreateImageIO(requestData, out, error);
+    #elif defined(__ANDROID__)
+    return ffImageCreateAID(requestData, out, error);
    #else
        #ifdef FF_HAVE_IMAGEMAGICK7
    if (ffImageCreateIM7(requestData, out, error)) {
@@ -879,6 +881,8 @@ bool ffImageAnimationOpen(FFLogoRequestData* requestData, FFImageAnimation** out
    return ffImageAnimationOpenWIC(requestData, out, error);
    #elif defined(__APPLE__)
    return ffImageAnimationOpenImageIO(requestData, out, error);
+    #elif defined(__ANDROID__)
+    return ffImageAnimationOpenAID(requestData, out, error);
    #elif defined(FF_HAVE_IMAGEMAGICK7)
    return ffImageAnimationOpenIM7(requestData, out, error);
    #else
@@ -915,10 +919,10 @@ void ffImageAnimationClose(FFImageAnimation* animation) {
 }

 bool ffImageSixelEncode(FFLogoRequestData* requestData, FFstrbuf* out, const char** error) {
-    // Windows (WIC) and macOS (ImageIO) decode and resize to RGBA first, then the embedded
-    // libsixel encoder takes over. Other platforms let ImageMagick encode straight from the
-    // decoded image without an RGBA round trip.
-    #if defined(_WIN32) || defined(__APPLE__)
+    // Windows (WIC), macOS (ImageIO) and Android (AImageDecoder) decode and resize to RGBA first,
+    // then the embedded libsixel encoder takes over. Other platforms let ImageMagick encode
+    // straight from the decoded image without an RGBA round trip.
+    #if defined(_WIN32) || defined(__APPLE__) || defined(__ANDROID__)
        #ifdef FF_HAVE_SIXEL
    FFImageBuffer buffer = {};
    if (!ffImageCreate(requestData, &buffer, error)) {
@@ -950,10 +954,10 @@ bool ffImageSixelEncode(FFLogoRequestData* requestData, FFstrbuf* out, const cha
 }

 bool ffImageSixelEncodeBuffer(const FFImageBuffer* buffer, FFstrbuf* out, const char** error) {
-    // Windows and macOS hand the pixels to the embedded encoder. ImageMagick has no way to encode
-    // pixels it was not given an Image for, so its SIXEL coder is reached through a ConstituteImage
-    // round trip instead.
-    #if defined(_WIN32) || defined(__APPLE__)
+    // Windows, macOS and Android hand the pixels to the embedded encoder. ImageMagick has no way to
+    // encode pixels it was not given an Image for, so its SIXEL coder is reached through a
+    // ConstituteImage round trip instead.
+    #if defined(_WIN32) || defined(__APPLE__) || defined(__ANDROID__)
        #ifdef FF_HAVE_SIXEL
    return ffSixelEncode(buffer, out, error);
        #else
@@ -1780,7 +1784,7 @@ bool ffLogoPrintImageIfExists(FFLogoType type, bool printError) {
    }
 #endif

-#if !defined(_WIN32) && !defined(__APPLE__) && !defined(FF_HAVE_IMAGEMAGICK7) && !defined(FF_HAVE_IMAGEMAGICK6)
+#if !defined(_WIN32) && !defined(__APPLE__) && !defined(__ANDROID__) && !defined(FF_HAVE_IMAGEMAGICK7) && !defined(FF_HAVE_IMAGEMAGICK6)
    if (printError) {
        fputs("Logo: Image Magick support is not compiled in\n", stderr);
    }
@@ -2,7 +2,7 @@

 #include "../logo.h"

-#if defined(FF_HAVE_IMAGEMAGICK7) || defined(FF_HAVE_IMAGEMAGICK6) || defined(_WIN32) || defined(__APPLE__) || defined(FF_HAVE_SIXEL)
+#if defined(FF_HAVE_IMAGEMAGICK7) || defined(FF_HAVE_IMAGEMAGICK6) || defined(_WIN32) || defined(__APPLE__) || defined(__ANDROID__) || defined(FF_HAVE_SIXEL)

 typedef enum FFLogoImageResult: uint8_t {
    FF_LOGO_IMAGE_RESULT_SUCCESS,    // Logo printed
@@ -119,6 +119,11 @@ bool ffImageCreateImageIO(FFLogoRequestData* requestData, FFImageBuffer* out, co
 bool ffImageAnimationOpenImageIO(FFLogoRequestData* requestData, FFImageAnimation** out, const char** error);
 #endif

+#ifdef __ANDROID__
+bool ffImageCreateAID(FFLogoRequestData* requestData, FFImageBuffer* out, const char** error);
+bool ffImageAnimationOpenAID(FFLogoRequestData* requestData, FFImageAnimation** out, const char** error);
+#endif
+
 #ifdef FF_HAVE_SIXEL
 bool ffSixelEncode(const FFImageBuffer* buffer, FFstrbuf* result, const char** error);
 #endif