diff --git a/sherpa-onnx/csrc/wave-reader.cc b/sherpa-onnx/csrc/wave-reader.cc index 505f18b9..e04e024a 100644 --- a/sherpa-onnx/csrc/wave-reader.cc +++ b/sherpa-onnx/csrc/wave-reader.cc @@ -25,7 +25,6 @@ #include namespace sherpa_onnx { - namespace { // see http://soundfile.sapp.org/doc/WaveFormat/ // @@ -33,10 +32,10 @@ namespace { // TODO(fangjun): Support big endian struct WaveHeader { void Validate() const { - // F F I R + // F F I R assert(chunk_id == 0x46464952); assert(chunk_size == 36 + subchunk2_size); - // E V A W + // E V A W assert(format == 0x45564157); assert(subchunk1_id == 0x20746d66); assert(subchunk1_size == 16); // 16 for PCM @@ -47,6 +46,22 @@ struct WaveHeader { assert(bits_per_sample == 16); // we support only 16 bits per sample } + // See + // https://en.wikipedia.org/wiki/WAV#Metadata + // and + // https://www.robotplanet.dk/audio/wav_meta_data/riff_mci.pdf + void SeekToDataChunk(std::istream &is) { + // a t a d + while (subchunk2_id != 0x61746164) { + // const char *p = reinterpret_cast(&subchunk2_id); + // printf("Skip chunk (%x): %c%c%c%c of size: %d\n", subchunk2_id, p[0], + // p[1], p[2], p[3], subchunk2_size); + is.seekg(subchunk2_size, std::istream::cur); + is.read(reinterpret_cast(&subchunk2_id), sizeof(int32_t)); + is.read(reinterpret_cast(&subchunk2_size), sizeof(int32_t)); + } + } + int32_t chunk_id; int32_t chunk_size; int32_t format; @@ -58,8 +73,8 @@ struct WaveHeader { int32_t byte_rate; int16_t block_align; int16_t bits_per_sample; - int32_t subchunk2_id; - int32_t subchunk2_size; + int32_t subchunk2_id; // a tag of this chunk + int32_t subchunk2_size; // size of subchunk2 }; static_assert(sizeof(WaveHeader) == 44, ""); @@ -69,9 +84,10 @@ std::vector ReadWaveImpl(std::istream &is, float *sample_rate) { WaveHeader header; is.read(reinterpret_cast(&header), sizeof(header)); assert(static_cast(is)); - header.Validate(); + header.SeekToDataChunk(is); + *sample_rate = header.sample_rate; // header.subchunk2_size contains the number of bytes in the data.