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#pragma once
#include "defs.h"
namespace ffmpeg {
/**
* Class uses internal buffer to store initial size bytes as a seekable cache
* from Media provider and let ffmpeg to seek and read bytes from cache
* and beyond - reading bytes directly from Media provider
*/
enum class ImageType {
UNKNOWN = 0,
JPEG = 1,
PNG = 2,
TIFF = 3,
};
class SeekableBuffer {
public:
// @type is optional, not nullptr only is image detection required
// \returns 1 is buffer seekable, 0 - if not seekable, < 0 on error
int init(
DecoderInCallback&& in,
uint64_t timeoutMs,
size_t maxSeekableBytes,
ImageType* type);
int read(uint8_t* buf, int size, uint64_t timeoutMs);
int64_t seek(int64_t offset, int whence, uint64_t timeoutMs);
void shutdown();
private:
bool readBytes(DecoderInCallback& in, size_t maxBytes, uint64_t timeoutMs);
void setImageType(ImageType* type);
private:
DecoderInCallback inCallback_;
std::vector<uint8_t> buffer_; // resized at init time
long pos_{0}; // current position (SEEK_CUR iff pos_ < end_)
long end_{0}; // current buffer size
bool eof_{0}; // indicates the EOF
bool isSeekable_{false}; // is callback seekable
};
} // namespace ffmpeg
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