ladybird/Userland/Libraries/LibAudio/Loader.h
2022-04-01 21:24:45 +01:00

86 lines
3 KiB
C++

/*
* Copyright (c) 2018-2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/NonnullOwnPtr.h>
#include <AK/NonnullRefPtr.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/Result.h>
#include <AK/Span.h>
#include <AK/StringView.h>
#include <AK/Try.h>
#include <LibAudio/Buffer.h>
#include <LibAudio/LoaderError.h>
#include <LibCore/File.h>
namespace Audio {
static constexpr StringView no_plugin_error = "No loader plugin available";
using LoaderSamples = Result<NonnullRefPtr<Buffer>, LoaderError>;
using MaybeLoaderError = Result<void, LoaderError>;
class LoaderPlugin {
public:
virtual ~LoaderPlugin() = default;
virtual MaybeLoaderError initialize() = 0;
virtual LoaderSamples get_more_samples(size_t max_bytes_to_read_from_input = 128 * KiB) = 0;
virtual MaybeLoaderError reset() = 0;
virtual MaybeLoaderError seek(int const sample_index) = 0;
// total_samples() and loaded_samples() should be independent
// of the number of channels.
//
// For example, with a three-second-long, stereo, 44.1KHz audio file:
// num_channels() should return 2
// sample_rate() should return 44100 (each channel is sampled at this rate)
// total_samples() should return 132300 (sample_rate * three seconds)
virtual int loaded_samples() = 0;
virtual int total_samples() = 0;
virtual u32 sample_rate() = 0;
virtual u16 num_channels() = 0;
// Human-readable name of the file format, of the form <full abbreviation> (.<ending>)
virtual String format_name() = 0;
virtual PcmSampleFormat pcm_format() = 0;
virtual RefPtr<Core::File> file() = 0;
};
class Loader : public RefCounted<Loader> {
public:
static Result<NonnullRefPtr<Loader>, LoaderError> create(StringView path) { return adopt_ref(*new Loader(TRY(try_create(path)))); }
static Result<NonnullRefPtr<Loader>, LoaderError> create(Bytes& buffer) { return adopt_ref(*new Loader(TRY(try_create(buffer)))); }
LoaderSamples get_more_samples(size_t max_bytes_to_read_from_input = 128 * KiB) const { return m_plugin->get_more_samples(max_bytes_to_read_from_input); }
MaybeLoaderError reset() const { return m_plugin->reset(); }
MaybeLoaderError seek(int const position) const { return m_plugin->seek(position); }
int loaded_samples() const { return m_plugin->loaded_samples(); }
int total_samples() const { return m_plugin->total_samples(); }
u32 sample_rate() const { return m_plugin->sample_rate(); }
u16 num_channels() const { return m_plugin->num_channels(); }
String format_name() const { return m_plugin->format_name(); }
u16 bits_per_sample() const { return pcm_bits_per_sample(m_plugin->pcm_format()); }
RefPtr<Core::File> file() const { return m_plugin->file(); }
private:
static Result<NonnullOwnPtr<LoaderPlugin>, LoaderError> try_create(StringView path);
static Result<NonnullOwnPtr<LoaderPlugin>, LoaderError> try_create(Bytes& buffer);
explicit Loader(NonnullOwnPtr<LoaderPlugin>);
mutable NonnullOwnPtr<LoaderPlugin> m_plugin;
};
}