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Implement lossless jpeg progression

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Ilya Fedin 2023-01-09 04:19:18 +04:00 • committed by John Preston
parent b67cff089c
commit 3c261d254e
2 changed files with 85 additions and 0 deletions
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84
ui/image/image_prepare.cpp
View file

@ -1293,4 +1293,88 @@ bool IsProgressiveJpeg(const QByteArray &bytes) {
return (info.progressive_mode > 0);
}
QByteArray MakeProgressiveJpeg(const QByteArray &bytes) {
struct jpeg_decompress_struct srcinfo;
struct jpeg_compress_struct dstinfo;
struct my_error_mgr jerr;
srcinfo.err = jpeg_std_error(&jerr);
dstinfo.err = jpeg_std_error(&jerr);
jerr.error_exit = my_error_exit;
if (setjmp(jerr.setjmp_buffer)) {
return {};
}
jpeg_create_decompress(&srcinfo);
const auto srcguard = gsl::finally([&] {
jpeg_abort_decompress(&srcinfo);
jpeg_destroy_decompress(&srcinfo);
});
jpeg_create_compress(&dstinfo);
const auto dstguard = gsl::finally([&] {
jpeg_abort_compress(&dstinfo);
jpeg_destroy_compress(&dstinfo);
});
jpeg_mem_src(
&srcinfo,
reinterpret_cast<const unsigned char*>(bytes.data()),
bytes.size());
jpeg_save_markers(&srcinfo, JPEG_COM, 0xFFFF);
for (int m = 0; m < 16; m++) {
jpeg_save_markers(&srcinfo, JPEG_APP0 + m, 0xFFFF);
}
jpeg_read_header(&srcinfo, true);
const auto coefArrays = jpeg_read_coefficients(&srcinfo);
jpeg_copy_critical_parameters(&srcinfo, &dstinfo);
jpeg_simple_progression(&dstinfo);
unsigned char* outbuffer = nullptr;
long unsigned int outsize = 0;
jpeg_mem_dest(&dstinfo, &outbuffer, &outsize);
const auto outbufferGuard = gsl::finally([&] {
free(outbuffer);
});
jpeg_write_coefficients(&dstinfo, coefArrays);
for (jpeg_saved_marker_ptr marker = srcinfo.marker_list
; marker != nullptr
; marker = marker->next) {
if (dstinfo.write_JFIF_header
&& marker->marker == JPEG_APP0
&& marker->data_length >= 5
&& marker->data[0] == 0x4A
&& marker->data[1] == 0x46
&& marker->data[2] == 0x49
&& marker->data[3] == 0x46
&& marker->data[4] == 0)
continue; // reject duplicate JFIF
if (dstinfo.write_Adobe_marker
&& marker->marker == JPEG_APP0 + 14
&& marker->data_length >= 5
&& marker->data[0] == 0x41
&& marker->data[1] == 0x64
&& marker->data[2] == 0x6F
&& marker->data[3] == 0x62
&& marker->data[4] == 0x65)
continue; // reject duplicate Adobe
jpeg_write_marker(
&dstinfo,
marker->marker,
marker->data,
marker->data_length);
}
jpeg_finish_compress(&dstinfo);
jpeg_finish_decompress(&srcinfo);
return QByteArray::fromRawData(
reinterpret_cast<char*>(outbuffer),
outsize);
}
} // namespace Images

1
ui/image/image_prepare.h
View file

@ -204,5 +204,6 @@ struct PrepareArgs {
}
[[nodiscard]] bool IsProgressiveJpeg(const QByteArray &bytes);
[[nodiscard]] QByteArray MakeProgressiveJpeg(const QByteArray &bytes);
} // namespace Images