int32_t
FrameParser::FrameHeader::SampleRate() const {
// Sample rates - use [version][srate]
static const uint16_t SAMPLE_RATE[4][4] = {
{ 11025, 12000, 8000, 0 }, // MPEG 2.5
{ 0, 0, 0, 0 }, // Reserved
{ 22050, 24000, 16000, 0 }, // MPEG 2
{ 44100, 48000, 32000, 0 } // MPEG 1
};
return SAMPLE_RATE[RawVersion()][RawSampleRate()];
}
bool FrameParser::FrameHeader::IsValid(int aPos) const {
if (aPos >= SIZE) {
return true;
}
if (aPos == frame_header::SYNC1) {
return Sync1() == 0xFF;
}
if (aPos == frame_header::SYNC2_VERSION_LAYER_PROTECTION) {
return Sync2() == 7 && RawVersion() != 1 && Layer() == 3;
}
if (aPos == frame_header::BITRATE_SAMPLERATE_PADDING_PRIVATE) {
return RawBitrate() != 0xF && RawBitrate() != 0 && RawSampleRate() != 3;
}
return true;
}