Unbreak Futatabi software (non-VA-API) MJPEG decoding.

This was all broken after adc0df0, it seems. It not only assumed 4:2:2,
but had broken chroma pitch, too.

diff --git a/futatabi/jpeg_frame_view.cpp b/futatabi/jpeg_frame_view.cpp
index 85c708d4d20f9aff8f137d0d3573b489d9a368f5..ff4fcb8242d7e0d565b4de840d3af30f3506c840 100644 (file)
--- a/futatabi/jpeg_frame_view.cpp
+++ b/futatabi/jpeg_frame_view.cpp
@@ -163,13 +163,15 @@ shared_ptr<Frame> decode_jpeg(const string &jpeg)
        unsigned chroma_width_blocks = mcu_width_blocks * dinfo.comp_info[1].h_samp_factor;
 
        PBO pbo = global_pbo_pool->alloc_pbo();
+       const size_t chroma_width = dinfo.image_width / frame->chroma_subsampling_x;
+       const size_t chroma_height = dinfo.image_height / frame->chroma_subsampling_y;
        size_t cb_offset = dinfo.image_width * dinfo.image_height;
-       size_t cr_offset = cb_offset + (dinfo.image_width / 2) * dinfo.image_height;
+       size_t cr_offset = cb_offset + chroma_width * chroma_height;
        uint8_t *y_pix = pbo.ptr;
        uint8_t *cb_pix = pbo.ptr + cb_offset;
        uint8_t *cr_pix = pbo.ptr + cr_offset;
        unsigned pitch_y = luma_width_blocks * DCTSIZE;
-       unsigned pitch_chroma = chroma_width_blocks * DCTSIZE * 2;
+       unsigned pitch_chroma = chroma_width_blocks * DCTSIZE;
 
        if (dinfo.marker_list != nullptr &&
            dinfo.marker_list->marker == JPEG_APP0 + 1 &&
@@ -201,11 +203,11 @@ shared_ptr<Frame> decode_jpeg(const string &jpeg)
        // FIXME: what about resolutions that are not divisible by the block factor?
        glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo.pbo);
        frame->y = create_texture_2d(frame->width, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
-       frame->cb = create_texture_2d(frame->width / 2, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cb_offset));
-       frame->cr = create_texture_2d(frame->width / 2, frame->height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cr_offset));
+       frame->cb = create_texture_2d(chroma_width, chroma_height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cb_offset));
+       frame->cr = create_texture_2d(chroma_width, chroma_height, GL_R8, GL_RED, GL_UNSIGNED_BYTE, BUFFER_OFFSET(cr_offset));
        glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
 
-       glFlushMappedNamedBufferRange(pbo.pbo, 0, dinfo.image_width * dinfo.image_height * 2);
+       glFlushMappedNamedBufferRange(pbo.pbo, 0, dinfo.image_width * dinfo.image_height + chroma_width * chroma_height * 2);
        glMemoryBarrier(GL_PIXEL_BUFFER_BARRIER_BIT);
        pbo.upload_done = RefCountedGLsync(GL_SYNC_GPU_COMMANDS_COMPLETE, /*flags=*/0);
        frame->uploaded_ui_thread = pbo.upload_done;