Method findAndDecodeFrame

src/fl/codec/mp3.cpp.hpp:250–330

}

bool Mp3StreamDecoderImpl::findAndDecodeFrame(audio::Sample* out_sample) {
    if (!mDecoder) {
        return false;
    }

    // Try to decode from current buffer
    const fl::u8* inptr = mBuffer.data() + mBufferPos;
    fl::size bytes_left = mBufferFilled - mBufferPos;

    if (bytes_left == 0) {
        return false;
    }

    // Find sync word
    int offset = mDecoder->findSyncWord(inptr, bytes_left);
    if (offset < 0) {
        // No sync word found, consume buffer and try again
        mBufferPos = mBufferFilled;
        return false;
    }

    inptr += offset;
    bytes_left -= offset;
    mBufferPos += offset;

    // Try to decode one frame
    const fl::u8* decode_ptr = inptr;
    fl::size decode_bytes = bytes_left;

    int result = mDecoder->decodeFrame(&decode_ptr, &decode_bytes);

    // Update buffer position based on how many bytes were consumed
    fl::size consumed = (decode_ptr - inptr);
    mBufferPos += consumed;
    mBytesProcessed += consumed;

    if (result == 0) {
        // Successfully decoded a frame
        Mp3Frame frame;
        frame.pcm = mDecoder->mPcmBuffer.get();
        frame.samples = mDecoder->mFrameInfo.outputSamps / mDecoder->mFrameInfo.nChans;
        frame.channels = mDecoder->mFrameInfo.nChans;
        frame.sample_rate = mDecoder->mFrameInfo.samprate;
        frame.bitrate = mDecoder->mFrameInfo.bitrate;
        frame.version = mDecoder->mFrameInfo.version;
        frame.layer = mDecoder->mFrameInfo.layer;

        // Update stream info on first successful decode
        if (!mHasDecodedFirstFrame) {
            mInfo.sampleRate = frame.sample_rate;
            mInfo.channels = static_cast<fl::u8>(frame.channels);
            mInfo.bitrate = frame.bitrate;
            mInfo.version = static_cast<fl::u8>(frame.version);
            mInfo.layer = static_cast<fl::u8>(frame.layer);
            mInfo.isValid = true;
            mHasDecodedFirstFrame = true;
        }