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opj_decode_tile_data takes a long time to decode a very small file #1524

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radarhere opened this issue Apr 15, 2024 · 0 comments · Fixed by #1526
Closed

opj_decode_tile_data takes a long time to decode a very small file #1524

radarhere opened this issue Apr 15, 2024 · 0 comments · Fixed by #1526

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@radarhere
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Expected behavior and actual behavior.

Expected: Very small files should be quick to decode (or quick to raise an error).
Actual: I've found opj_decode_tile_data() takes 52 seconds to process a specific 83 byte image.

Steps to reproduce the problem.

Here is my attempt at a minimal reproduction, removing error handling and other code that is not strictly necessary to demonstrate this. I've attached the 'image' file as a zip. On my Apple M1, running the code prints

Time spent on opj_decode_tile_data 52.414478

typedef struct {
    OPJ_UINT32 tile_index;
    OPJ_UINT32 data_size;
    OPJ_INT32 x0, y0, x1, y1;
    OPJ_UINT32 nb_comps;
} JPEG2KTILEINFO;

static OPJ_SIZE_T
j2k_read(void *p_buffer, OPJ_SIZE_T p_nb_bytes, void *p_user_data) {
    FILE *f = fopen("image", "rb");
    fread(p_buffer, 1, 83, f);
    return 83;
}

struct State {
    UINT8 *buffer;
};

struct State *state = malloc(sizeof(struct State));
opj_stream_t *stream = NULL;
opj_image_t *image = NULL;
opj_codec_t *codec = NULL;
opj_dparameters_t params;

stream = opj_stream_create(OPJ_J2K_STREAM_CHUNK_SIZE, OPJ_TRUE);

opj_stream_set_read_function(stream, j2k_read);

opj_stream_set_user_data(stream, state, NULL);

opj_stream_set_user_data_length(stream, 83);

opj_set_default_decoder_parameters(&params);
params.cp_reduce = 0;
params.cp_layer = 0;

codec = opj_create_decompress(OPJ_CODEC_J2K);

opj_setup_decoder(codec, &params);

opj_read_header(stream, codec, &image);
JPEG2KTILEINFO tile_info;
OPJ_BOOL should_continue;

opj_read_tile_header(
        codec,
        stream,
        &tile_info.tile_index,
        &tile_info.data_size,
        &tile_info.x0,
        &tile_info.y0,
        &tile_info.x1,
        &tile_info.y1,
        &tile_info.nb_comps,
        &should_continue);

state->buffer = malloc(tile_info.data_size);

clock_t begin = clock();
opj_decode_tile_data(
    codec,
    tile_info.tile_index,
    (OPJ_BYTE *)state->buffer,
    tile_info.data_size,
    stream);
clock_t end = clock();
double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
printf("Time spent on opj_decode_tile_data %f\n", time_spent);

image.zip

Operating system

macOS 14.4.1

openjpeg version

2.5.2

Thanks for your time.

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