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minor improvement for better code readibility

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This commit is contained in:
Suleyman TURKMEN 2025-01-24 15:31:53 +03:00
parent 9bb01e799f
commit ca51d55ee3
2 changed files with 50 additions and 18 deletions
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41
modules/imgcodecs/src/grfmt_png.cpp
View File

@ -274,7 +274,7 @@ bool PngDecoder::readHeader()
}
// Read PNG header: 137 80 78 71 13 10 26 10
if (!read_from_io(&sig, 8))
if (!readFromStreamOrBuffer(&sig, 8))
return false;
id = read_chunk(m_chunkIHDR);
@ -682,7 +682,7 @@ void PngDecoder::compose_frame(std::vector<png_bytep>& rows_dst, const std::vect
});
}
bool PngDecoder::read_from_io(void* buffer, size_t num_bytes)
bool PngDecoder::readFromStreamOrBuffer(void* buffer, size_t num_bytes)
{
if (m_f)
return fread(buffer, 1, num_bytes, m_f) == num_bytes;
@ -700,7 +700,7 @@ bool PngDecoder::read_from_io(void* buffer, size_t num_bytes)
uint32_t PngDecoder::read_chunk(Chunk& chunk)
{
unsigned char size_id[8];
if (!read_from_io(&size_id, 8))
if (!readFromStreamOrBuffer(&size_id, 8))
return 0;
const size_t size = static_cast<size_t>(png_get_uint_32(size_id)) + 12;
@ -737,7 +737,7 @@ uint32_t PngDecoder::read_chunk(Chunk& chunk)
chunk.p.resize(size);
memcpy(chunk.p.data(), size_id, 8);
if (read_from_io(&chunk.p[8], chunk.p.size() - 8))
if (readFromStreamOrBuffer(&chunk.p[8], chunk.p.size() - 8))
return id;
return 0;
}
@ -960,15 +960,24 @@ bool PngEncoder::write( const Mat& img, const std::vector<int>& params )
return result;
}
size_t PngEncoder::write_to_io(void const* _Buffer, size_t _ElementSize, size_t _ElementCount, FILE * _Stream)
size_t PngEncoder::writeToStreamOrBuffer(void const* buffer, size_t num_bytes, FILE* stream)
{
if (_Stream)
return fwrite(_Buffer, _ElementSize, _ElementCount, _Stream);
if (!buffer || !num_bytes)
return 0; // Handle null buffer or empty writes
if (stream)
{
size_t written = fwrite(buffer, 1, num_bytes, stream);
return written; // fwrite handles the write count
}
size_t cursz = m_buf->size();
m_buf->resize(cursz + _ElementCount);
memcpy( &(*m_buf)[cursz], _Buffer, _ElementCount );
return _ElementCount;
if (cursz + num_bytes > m_buf->max_size())
throw std::runtime_error("Buffer size exceeds maximum capacity");
m_buf->resize(cursz + num_bytes);
memcpy(&(*m_buf)[cursz], buffer, num_bytes);
return num_bytes;
}
void PngEncoder::writeChunk(FILE* f, const char* name, unsigned char* data, uint32_t length)
@ -977,26 +986,26 @@ void PngEncoder::writeChunk(FILE* f, const char* name, unsigned char* data, uint
uint32_t crc = crc32(0, Z_NULL, 0);
png_save_uint_32(buf, length);
write_to_io(buf, 1, 4, f);
write_to_io(name, 1, 4, f);
writeToStreamOrBuffer(buf, 4, f);
writeToStreamOrBuffer(name, 4, f);
crc = crc32(crc, (const Bytef*)name, 4);
if (memcmp(name, "fdAT", 4) == 0)
{
png_save_uint_32(buf, next_seq_num++);
write_to_io(buf, 1, 4, f);
writeToStreamOrBuffer(buf, 4, f);
crc = crc32(crc, buf, 4);
length -= 4;
}
if (data != NULL && length > 0)
{
write_to_io(data, 1, length, f);
writeToStreamOrBuffer(data, length, f);
crc = crc32(crc, data, length);
}
png_save_uint_32(buf, crc);
write_to_io(buf, 1, 4, f);
writeToStreamOrBuffer(buf, 4, f);
}
void PngEncoder::writeIDATs(FILE* f, int frame, unsigned char* data, uint32_t length, uint32_t idat_size)
@ -1521,7 +1530,7 @@ bool PngEncoder::writeanimation(const Animation& animation, const std::vector<in
png_save_uint_32(buf_acTL, num_frames - first);
png_save_uint_32(buf_acTL + 4, loops);
write_to_io(header, 1, 8, m_f);
writeToStreamOrBuffer(header, 8, m_f);
writeChunk(m_f, "IHDR", buf_IHDR, 13);

27
modules/imgcodecs/src/grfmt_png.hpp
View File

@ -137,7 +137,13 @@ private:
CV_NODISCARD_STD bool processing_start(void* frame_ptr, const Mat& img);
CV_NODISCARD_STD bool processing_finish();
void compose_frame(std::vector<png_bytep>& rows_dst, const std::vector<png_bytep>& rows_src, unsigned char bop, uint32_t x, uint32_t y, uint32_t w, uint32_t h, Mat& img);
CV_NODISCARD_STD bool read_from_io(void* buffer, size_t num_bytes);
/**
* @brief Reads data from an I/O source into the provided buffer.
* @param buffer Pointer to the buffer where the data will be stored.
* @param num_bytes Number of bytes to read into the buffer.
* @return true if the operation is successful, false otherwise.
*/
CV_NODISCARD_STD bool readFromStreamOrBuffer(void* buffer, size_t num_bytes);
uint32_t read_chunk(Chunk& chunk);
CV_NODISCARD_STD bool InitPngPtr();
void ClearPngPtr();
@ -185,7 +191,24 @@ public:
protected:
static void writeDataToBuf(void* png_ptr, unsigned char* src, size_t size);
static void flushBuf(void* png_ptr);
size_t write_to_io(void const* _Buffer, size_t _ElementSize, size_t _ElementCount, FILE* _Stream);
/**
* @brief Writes data to an output destination, either a file stream or an in-memory buffer.
*
* This function handles two output scenarios:
* 1. If a file stream is provided, the data is written to the stream using `fwrite`.
* 2. If `stream` is null, the data is written to an in-memory buffer (`m_buf`), which is resized as needed.
*
* @param buffer Pointer to the data to be written.
* @param num_bytes The number of bytes to be written.
* @param stream Pointer to the file stream for writing. If null, the data is written to the in-memory buffer.
* @return The number of bytes successfully written.
* - For file-based writes, this is the number of bytes written to the stream.
* - For buffer-based writes, this is the total number of bytes added to the buffer.
*
* @throws std::runtime_error If the in-memory buffer (`m_buf`) exceeds its maximum capacity.
* @note If `num_bytes` is 0 or `buffer` is null, the function returns 0.
*/
size_t writeToStreamOrBuffer(void const* buffer, size_t num_bytes, FILE* stream);
private:
void writeChunk(FILE* f, const char* name, unsigned char* data, uint32_t length);