201 lines
7.3 KiB
C++
201 lines
7.3 KiB
C++
/***
|
|
|
|
Olive - Non-Linear Video Editor
|
|
Copyright (C) 2019 Olive Team
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
***/
|
|
|
|
#ifndef DECODER_H
|
|
#define DECODER_H
|
|
|
|
#include <QObject>
|
|
#include <stdint.h>
|
|
|
|
#include "common/rational.h"
|
|
#include "project/item/footage/footage.h"
|
|
#include "decoder/frame.h"
|
|
|
|
class Decoder;
|
|
using DecoderPtr = std::shared_ptr<Decoder>;
|
|
|
|
/**
|
|
* @brief A decoder's is the main class for bringing external media into Olive
|
|
*
|
|
* Its responsibilities are to serve as
|
|
* abstraction from codecs/decoders and provide complete frames. These frames can be video or audio data and are
|
|
* provided as Frame objects in shared pointers to alleviate the responsibility of memory handling.
|
|
*
|
|
* The main function in a decoder is Retrieve() which should return complete image/audio data. A decoder should
|
|
* alleviate all the complexities of codec compression from the rest of the application (i.e. a decoder should never
|
|
* return a partial frame or require other parts of the system to interface directly with the codec). Often this will
|
|
* necessitate pre-emptively caching, indexing, or even fully transcoding media before using it which can be implemented
|
|
* through the Analyze() function.
|
|
*
|
|
* A decoder does NOT perform any pixel/sample format conversion. Frames should pass through the PixelFormatConverter
|
|
* (olive::pix_fmt_conv) to be utilized in the rest of the rendering pipeline.
|
|
*/
|
|
class Decoder : public QObject
|
|
{
|
|
Q_OBJECT
|
|
public:
|
|
Decoder();
|
|
|
|
Decoder(Stream* fs);
|
|
|
|
// Necessary for subclassing, it's empty
|
|
virtual ~Decoder();
|
|
|
|
/**
|
|
* @brief Deleted copy constructor
|
|
*/
|
|
Decoder(const Decoder& other) = delete;
|
|
|
|
/**
|
|
* @brief Deleted move constructor
|
|
*/
|
|
Decoder(Decoder&& other) = delete;
|
|
|
|
/**
|
|
* @brief Deleted copy assignment
|
|
*/
|
|
Decoder& operator=(const Decoder& other) = delete;
|
|
|
|
/**
|
|
* @brief Deleted move assignment
|
|
*/
|
|
Decoder& operator=(Decoder&& other) = delete;
|
|
|
|
virtual QString id() = 0;
|
|
|
|
const Stream* stream();
|
|
void set_stream(const Stream *fs);
|
|
|
|
/**
|
|
* @brief Probe a footage file and dump metadata about it
|
|
*
|
|
* When a Footage file is imported, we'll need to know whether Olive is equipped with a decoder for utilizing it
|
|
* and metadata should be retrieved about it if so. For this purpose, the Footage object is passed through all
|
|
* Probe() functions of available deocders until one returns TRUE. A FALSE return means the Decoder was unable to
|
|
* parse this file and the next should be tried.
|
|
*
|
|
* Probe() differs from Open() since it focuses on a file as a whole rather than one particular stream. Probe()
|
|
* should be able to be run directly without calling Open() or Close() and should free its memory before returning.
|
|
*
|
|
* Probe() will never be called on an object that is also used for decoding. In other words, it will never be called
|
|
* alongside Open() or Close() externally, so Probe() can use variables that would otherwise be used for decoding
|
|
* without conflict.
|
|
*
|
|
* @param f
|
|
*
|
|
* A Footage object to probe. The Footage object will have a valid filename and will be empty prior to being sent
|
|
* to this function (i.e. Footage::Clear() will not have to be called).
|
|
*
|
|
* @return
|
|
*
|
|
* TRUE if the Decoder was able to decode this file. FALSE if not. This function should have filled the Footage
|
|
* object with metadata if it returns TRUE. Otherwise, the Footage object should be untouched.
|
|
*/
|
|
virtual bool Probe(Footage* f) = 0;
|
|
|
|
/**
|
|
* @brief Open media/allocate memory
|
|
*
|
|
* Any file handles or memory allocation that needs to be done before this instance of a Decoder can return data
|
|
* should be done here.
|
|
*
|
|
* @return
|
|
*
|
|
* TRUE if successful and ready to return data, FALSE if failed to open and unable to retrieve data. If the function
|
|
* fails, any memory allocated should be free'd before returning FALSE, possibly by calling Close().
|
|
*/
|
|
virtual bool Open() = 0;
|
|
|
|
/**
|
|
* @brief Retrieve frame/data
|
|
*
|
|
* The main function for retrieving data from the Decoder. This function should always provide complete frame data
|
|
* (i.e. no partial frames or missing samples) at the timecode provided. The Decoder should perform any steps
|
|
* required to retrieve a complete frame separate from the rest of the program, using any form of caching/indexing
|
|
* to keep this as performant as possible.
|
|
*
|
|
* It's acceptable for this function to check whether the Decoder is open, and call Open() if not. If Open() returns
|
|
* false, this function should return nullptr.
|
|
*
|
|
* @param timecode
|
|
*
|
|
* The timecode (a rational in seconds) to retrieve the data at.
|
|
*
|
|
* @param length
|
|
*
|
|
* Audio only - ignored for video decoders. The total length of audio data to retrieve (a rational in seconds).
|
|
*
|
|
* @return
|
|
*
|
|
* A FramePtr of valid data at this timecode (of the requested length if this is audio media), or nullptr if there
|
|
* was nothing to retrieve at the provided timecode or the media could not be opened.
|
|
*/
|
|
virtual FramePtr Retrieve(const rational& timecode, const rational& length = 0) = 0;
|
|
|
|
/**
|
|
* @brief Close media/deallocate memory
|
|
*
|
|
* Any file handles or memory allocations opened in Open() should be cleaned up here.
|
|
*
|
|
* As the main memory freeing function, it's good practice to call this in Open() if there's an error that prevents
|
|
* correct function before Open() returns. As such, Close() should be prepared for not all memory/file handles to
|
|
* have been opened successfully.
|
|
*/
|
|
virtual void Close() = 0;
|
|
|
|
/**
|
|
* @brief Try to probe a Footage file by passing it through all available Decoders
|
|
*
|
|
* This is a helper function designed to abstract the process of communicating with several Decoders from the rest of
|
|
* the application. This function will take a Footage file and manually pass it through the available Decoders' Probe()
|
|
* functions until one indicates that it can decode this file. That Decoder will then dump information about the file
|
|
* into the Footage object for use throughout the program.
|
|
*
|
|
* Probing may be a lengthy process and it's recommended to run this in a separate thread.
|
|
*
|
|
* @param f
|
|
*
|
|
* A Footage object with a valid filename. If the Footage does not have a valid filename (e.g. is empty or file doesn't
|
|
* exist), this function will return FALSE.
|
|
*
|
|
* @return
|
|
*
|
|
* TRUE if a Decoder was successfully able to parse and probe this file. FALSE if not.
|
|
*/
|
|
static bool ProbeMedia(Footage* f);
|
|
|
|
/**
|
|
* @brief Create a Decoder instance using a Decoder ID
|
|
*
|
|
* @return
|
|
*
|
|
* A Decoder instance or nullptr if a Decoder with this ID does not exist
|
|
*/
|
|
static DecoderPtr CreateFromID(const QString& id);
|
|
|
|
protected:
|
|
bool open_;
|
|
|
|
private:
|
|
const Stream* stream_;
|
|
};
|
|
|
|
#endif // DECODER_H
|