libtiff解析

src/io_uring_tile.c

@@ -0,0 +1,112 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <liburing.h>
+#include <tiffio.h>
+
+#define MAX_TILES 1024
+
+int main()
+{
+    // 打开 TIFF 文件
+    int fd = open("imgs/ortho.tif", O_RDONLY);
+    if (fd < 0)
+    {
+        perror("open");
+        return 1;
+    }
+
+    TIFF *tif = TIFFOpen("imgs/ortho.tif", "r");
+    if (!tif)
+    {
+        printf("Failed to open TIFF.\n");
+        close(fd);
+        return 1;
+    }
+
+    uint32 tileWidth, tileHeight;
+    TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tileWidth);
+    TIFFGetField(tif, TIFFTAG_TILELENGTH, &tileHeight);
+
+    uint32 imageWidth, imageHeight;
+    TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &imageWidth);
+    TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &imageHeight);
+
+    uint32 tilesAcross = (imageWidth + tileWidth - 1) / tileWidth;
+    uint32 tilesDown = (imageHeight + tileHeight - 1) / tileHeight;
+    uint32 totalTiles = tilesAcross * tilesDown;
+    if (totalTiles > MAX_TILES)
+    {
+        printf("Too many tiles (> %d)\n", MAX_TILES);
+        TIFFClose(tif);
+        close(fd);
+        return 1;
+    }
+
+    tsize_t *byteCounts = NULL;
+    toff_t *offsets = NULL;
+
+    TIFFGetField(tif, TIFFTAG_TILEBYTECOUNTS, &byteCounts);
+    TIFFGetField(tif, TIFFTAG_TILEOFFSETS, &offsets);
+
+    // 初始化 io_uring
+    struct io_uring ring;
+    io_uring_queue_init(totalTiles, &ring, 0);
+
+    // 分配 buffer 指针数组
+    char *buffers[MAX_TILES];
+
+    // 提交异步读请求
+    for (uint32 i = 0; i < totalTiles; i++)
+    {
+        buffers[i] = malloc(byteCounts[i]);
+        if (!buffers[i])
+        {
+            perror("malloc");
+            // 应该加清理，略
+            break;
+        }
+
+        struct io_uring_sqe *sqe = io_uring_get_sqe(&ring);
+        io_uring_prep_read(sqe, fd, buffers[i], byteCounts[i], offsets[i]);
+        io_uring_sqe_set_data(sqe, buffers[i]);
+    }
+
+    io_uring_submit(&ring);
+
+    // 等待所有完成
+    for (uint32 i = 0; i < totalTiles; i++)
+    {
+        struct io_uring_cqe *cqe;
+        int ret = io_uring_wait_cqe(&ring, &cqe);
+        if (ret < 0)
+        {
+            fprintf(stderr, "io_uring_wait_cqe error: %d\n", ret);
+            // 处理错误，略
+        }
+        if (cqe->res < 0)
+        {
+            fprintf(stderr, "Async read failed: %d\n", cqe->res);
+        }
+        else
+        {
+            // 成功读到 cqe->res 字节数据
+            char *data = io_uring_cqe_get_data(cqe);
+            // 这里 data 指向对应 tile 的缓冲区
+            // 你可以对 data 进一步解码处理
+        }
+        io_uring_cqe_seen(&ring, cqe);
+    }
+
+    // 清理
+    for (uint32 i = 0; i < totalTiles; i++)
+    {
+        free(buffers[i]);
+    }
+    io_uring_queue_exit(&ring);
+    TIFFClose(tif);
+    close(fd);
+
+    return 0;
+}

src/parse_tiff.c

@@ -0,0 +1,87 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <tiffio.h>
+
+int main()
+{
+    TIFF *tif = TIFFOpen("imgs/ortho.tif", "r");
+    if (!tif)
+    {
+        printf("Failed to open file.\n");
+        return 1;
+    }
+
+    uint32 tileWidth, tileHeight;
+    TIFFGetField(tif, TIFFTAG_TILEWIDTH, &tileWidth);
+    TIFFGetField(tif, TIFFTAG_TILELENGTH, &tileHeight);
+    printf("Tile size: %dx%d\n", tileWidth, tileHeight);
+
+    uint32 imageWidth, imageHeight;
+    TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &imageWidth);
+    TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &imageHeight);
+
+    uint32 tilesAcross = (imageWidth + tileWidth - 1) / tileWidth;
+    uint32 tilesDown = (imageHeight + tileHeight - 1) / tileHeight;
+    uint32 totalTiles = tilesAcross * tilesDown;
+    printf("Tile count: %d x %d = %d\n", tilesAcross, tilesDown, totalTiles);
+
+    uint16 samplesPerPixel;
+    uint16 bitsPerSample;
+
+    TIFFGetField(tif, TIFFTAG_SAMPLESPERPIXEL, &samplesPerPixel);
+    TIFFGetField(tif, TIFFTAG_BITSPERSAMPLE, &bitsPerSample);
+
+    printf("Samples per pixel: %d\n", samplesPerPixel);
+    printf("Bits per sample: %d\n", bitsPerSample);
+
+    uint16 sampleFormat = SAMPLEFORMAT_UINT;
+    TIFFGetField(tif, TIFFTAG_SAMPLEFORMAT, &sampleFormat);
+    printf("Sample format: %d\n", sampleFormat); // 1=uint, 2=int, 3=float
+
+    tsize_t tileBufSize = TIFFTileSize(tif);
+    if (tileBufSize == 0)
+    {
+        printf("TIFFTileSize returned 0. Possibly not tiled.\n");
+        TIFFClose(tif);
+        return 1;
+    }
+
+    // 分配一个缓冲区用于存放一个 tile 的像素数据（未压缩）
+    uint8_t *tileBuf = (uint8_t *)_TIFFmalloc(tileBufSize);
+    if (!tileBuf)
+    {
+        fprintf(stderr, "Failed to allocate tile buffer.\n");
+        TIFFClose(tif);
+        return 1;
+    }
+
+    // 遍历每个 tile 并解码为像素数据
+    for (uint32 i = 0; i < totalTiles; i++)
+    {
+        // 读取 tile 编号 i，解码为原始像素，存入 tileBuf
+        tsize_t readBytes = TIFFReadEncodedTile(tif, i, tileBuf, tileBufSize);
+        if (readBytes == -1)
+        {
+            fprintf(stderr, "Failed to decode tile %d\n", i);
+            continue;
+        }
+
+        printf("Tile %3d: Decoded %6ld bytes (uncompressed pixel data)\n",
+               i, (long)readBytes);
+
+        // 示例：打印前4个像素（假设每像素 samplesPerPixel 个 uint8 通道）
+        for (int px = 0; px < 4 && px < (readBytes / samplesPerPixel); px++)
+        {
+            printf("  Pixel %d: ", px);
+            for (int s = 0; s < samplesPerPixel; s++)
+            {
+                printf("%3u ", tileBuf[px * samplesPerPixel + s]);
+            }
+            printf("\n");
+        }
+    }
+
+    _TIFFfree(tileBuf);
+    TIFFClose(tif);
+    return 0;
+}