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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#if !defined(WavDumper_h_)
# define WavDumper_h_
# include <stdio.h>
# include <stdint.h>
# include <nsTArray.h>
# include <mozilla/Unused.h>
# include <mozilla/Atomics.h>
# include <mozilla/DebugOnly.h>
# include <mozilla/Sprintf.h>
# include <ByteWriter.h>
/**
* If MOZ_DUMP_AUDIO is set, this dumps a file to disk containing the output of
* an audio stream, in 16bits integers.
*
* The sandbox needs to be disabled for this to work.
*/
class WavDumper {
public:
WavDumper() = default;
~WavDumper() {
if (mFile) {
fclose(mFile);
}
}
void Open(const char* aBaseName, uint32_t aChannels, uint32_t aRate) {
using namespace mozilla;
if (!getenv("MOZ_DUMP_AUDIO")) {
return;
}
static mozilla::Atomic<int> sDumpedAudioCount(0);
char buf[100];
SprintfLiteral(buf, "%s-%d.wav", aBaseName, ++sDumpedAudioCount);
mFile = fopen(buf, "wb");
if (!mFile) {
NS_WARNING("Could not open file to DUMP a wav. Is sandboxing disabled?");
return;
}
const uint8_t riffHeader[] = {
// RIFF header
0x52, 0x49, 0x46, 0x46, 0x00, 0x00, 0x00, 0x00, 0x57, 0x41, 0x56, 0x45,
// fmt chunk. We always write 16-bit samples.
0x66, 0x6d, 0x74, 0x20, 0x10, 0x00, 0x00, 0x00, 0x01, 0x00, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x10, 0x00,
// data chunk
0x64, 0x61, 0x74, 0x61, 0xFE, 0xFF, 0xFF, 0x7F};
AutoTArray<uint8_t, sizeof(riffHeader)> header;
ByteWriter<LittleEndian> writer(header);
static const int CHANNEL_OFFSET = 22;
static const int SAMPLE_RATE_OFFSET = 24;
static const int BLOCK_ALIGN_OFFSET = 32;
DebugOnly<bool> rv;
// Then number of bytes written in each iteration.
uint32_t written = 0;
for (size_t i = 0; i != sizeof(riffHeader);) {
switch (i) {
case CHANNEL_OFFSET:
rv = writer.WriteU16(aChannels);
written = 2;
MOZ_ASSERT(rv);
break;
case SAMPLE_RATE_OFFSET:
rv = writer.WriteU32(aRate);
written = 4;
MOZ_ASSERT(rv);
break;
case BLOCK_ALIGN_OFFSET:
rv = writer.WriteU16(aChannels * 2);
written = 2;
MOZ_ASSERT(rv);
break;
default:
// copy from the riffHeader struct above
rv = writer.WriteU8(riffHeader[i]);
written = 1;
MOZ_ASSERT(rv);
break;
}
i += written;
}
Unused << fwrite(header.Elements(), header.Length(), 1, mFile);
}
template <typename T>
void Write(const T* aBuffer, uint32_t aSamples) {
if (!mFile) {
return;
}
WriteDumpFileHelper(aBuffer, aSamples);
}
private:
void WriteDumpFileHelper(const int16_t* aInput, size_t aSamples) {
mozilla::Unused << fwrite(aInput, sizeof(int16_t), aSamples, mFile);
fflush(mFile);
}
void WriteDumpFileHelper(const float* aInput, size_t aSamples) {
using namespace mozilla;
AutoTArray<uint8_t, 1024 * 2> buf;
ByteWriter<mozilla::LittleEndian> writer(buf);
for (uint32_t i = 0; i < aSamples; ++i) {
DebugOnly<bool> rv = writer.WriteU16(int16_t(aInput[i] * 32767.0f));
MOZ_ASSERT(rv);
}
mozilla::Unused << fwrite(buf.Elements(), buf.Length(), 1, mFile);
fflush(mFile);
}
FILE* mFile = nullptr;
};
#endif // WavDumper_h_