1/*
2 * Copyright 2008 Stephan Aßmus <superstippi@gmx.de>
3 * All rights reserved. Distributed under the terms of the MIT licensce.
4 */
5
6
7#include "AudioVolumeConverter.h"
8
9#include <stdio.h>
10#include <string.h>
11
12#include <MediaDefs.h>
13
14
15//#define TRACE_AUDIO_CONVERTER
16#ifdef TRACE_AUDIO_CONVERTER
17#	define TRACE(x...)	printf(x)
18#else
19#	define TRACE(x...)
20#endif
21
22
23template<typename SampleType>
24static void
25convert(SampleType* buffer, const int32 samples, const float volume,
26	const float rounding)
27{
28	for (int32 i = 0; i < samples; i++) {
29		*buffer = (SampleType)(*buffer * volume + rounding);
30		buffer++;
31	}
32}
33
34
35template<typename SampleType>
36static void
37convert(SampleType* buffer, const int32 frames, const int32 channels,
38	const float volume1, const float volume2, const float rounding)
39{
40	float volumeDiff = volume2 - volume1;
41	for (int32 i = 0; i < frames; i++) {
42		float volume = volume1 + volumeDiff * (i / (frames - 1));
43		for (int32 k = 0; k < channels; k++) {
44			*buffer = (SampleType)(*buffer * volume + rounding);
45			buffer++;
46		}
47	}
48}
49
50
51// #pragma mark -
52
53
54AudioVolumeConverter::AudioVolumeConverter(AudioReader* source, float volume)
55	:
56	AudioReader(),
57	fSource(NULL),
58	fVolume(volume),
59	fPreviousVolume(volume)
60{
61	if (source && source->Format().type == B_MEDIA_RAW_AUDIO)
62		fFormat = source->Format();
63	else
64		source = NULL;
65	fSource = source;
66}
67
68
69AudioVolumeConverter::~AudioVolumeConverter()
70{
71}
72
73
74bigtime_t
75AudioVolumeConverter::InitialLatency() const
76{
77	return fSource->InitialLatency();
78}
79
80
81status_t
82AudioVolumeConverter::Read(void* buffer, int64 pos, int64 frames)
83{
84	TRACE("AudioVolumeConverter::Read(%p, %lld, %lld)\n", buffer, pos, frames);
85	status_t error = InitCheck();
86	if (error != B_OK) {
87		TRACE("AudioVolumeConverter::Read() done 1\n");
88		return error;
89	}
90	pos += fOutOffset;
91
92	status_t ret = fSource->Read(buffer, pos, frames);
93	if (fPreviousVolume == 1.0 && fVolume == 1.0) {
94		TRACE("AudioVolumeConverter::Read() done 2\n");
95		return ret;
96	}
97
98	int32 channelCount = fFormat.u.raw_audio.channel_count;
99	int32 samples = frames * channelCount;
100
101	// apply volume
102	switch (fSource->Format().u.raw_audio.format) {
103		case media_raw_audio_format::B_AUDIO_FLOAT:
104			if (fVolume != fPreviousVolume) {
105				convert((float*)buffer, frames, channelCount,
106					fPreviousVolume, fVolume, 0.0);
107			} else
108				convert((float*)buffer, samples, fVolume, 0.0);
109			break;
110		case media_raw_audio_format::B_AUDIO_INT:
111			if (fVolume != fPreviousVolume) {
112				convert((int32*)buffer, frames, channelCount,
113					fPreviousVolume, fVolume, 0.5);
114			} else
115				convert((int32*)buffer, samples, fVolume, 0.5);
116			break;
117		case media_raw_audio_format::B_AUDIO_SHORT:
118			if (fVolume != fPreviousVolume) {
119				convert((int16*)buffer, frames, channelCount,
120					fPreviousVolume, fVolume, 0.5);
121			} else
122				convert((int16*)buffer, samples, fVolume, 0.5);
123			break;
124		case media_raw_audio_format::B_AUDIO_UCHAR: {
125			// handle this extra, because center != 0
126			// (also ignores ramping the volume)
127			uchar* b = (uchar*)buffer;
128			for (int32 i = 0; i < samples; i++) {
129				*b = (uchar)(((float)*b - 128) * fVolume + 128.5);
130				b++;
131			}
132			break;
133		}
134		case media_raw_audio_format::B_AUDIO_CHAR:
135			if (fVolume != fPreviousVolume) {
136				convert((int8*)buffer, frames, channelCount,
137					fPreviousVolume, fVolume, 0.0);
138			} else
139				convert((int8*)buffer, samples, fVolume, 0.5);
140			break;
141	}
142
143	fPreviousVolume = fVolume;
144
145	TRACE("AudioVolumeConverter::Read() done\n");
146	return B_OK;
147}
148
149
150status_t
151AudioVolumeConverter::InitCheck() const
152{
153	status_t error = AudioReader::InitCheck();
154	if (error == B_OK && !fSource)
155		error = B_NO_INIT;
156	if (error == B_OK)
157		error = fSource->InitCheck();
158	return error;
159}
160
161
162AudioReader*
163AudioVolumeConverter::Source() const
164{
165	return fSource;
166}
167
168
169void
170AudioVolumeConverter::SetVolume(float volume)
171{
172	fVolume = volume;
173}
174
175
176float
177AudioVolumeConverter::Volume() const
178{
179	return fVolume;
180}
181
182