OcWaveLib.c

Go to the documentation of this file.

 
#include <Uefi.h>
 
#include <IndustryStandard/Riff.h>
 
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/BaseOverflowLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/OcWaveLib.h>
 
EFI_STATUS
OcDecodeWave (
  IN  UINT8                       *Buffer,
  IN  UINTN                       BufferSize,
  OUT UINT8                       **RawBuffer,
  OUT UINT32                      *RawBufferSize,
  OUT EFI_AUDIO_IO_PROTOCOL_FREQ  *Frequency,
  OUT EFI_AUDIO_IO_PROTOCOL_BITS  *Bits,
  OUT UINT8                       *Channels
  )
{
  RIFF_CHUNK        *TmpChunk;
  WAVE_FORMAT_DATA  *WaveFormat;
  RIFF_CHUNK        *DataChunk;
  UINT8             *BufferPtr;
  UINT8             *BufferEnd;
 
  if (BufferSize < sizeof (RIFF_CHUNK) + RIFF_CHUNK_ID_SIZE) {
    return EFI_UNSUPPORTED;
  }
 
  TmpChunk = (RIFF_CHUNK *)Buffer;
 
  //
  // Ensure:
  // - File size validity
  // - Chunk ID is RIFF
  // - First 4 bytes of data are WAVE.
  //
  if (  ((UINT64)TmpChunk->Size + sizeof (RIFF_CHUNK) != BufferSize)
     || (AsciiStrnCmp (TmpChunk->Id, RIFF_CHUNK_ID, RIFF_CHUNK_ID_SIZE) != 0)
     || (AsciiStrnCmp ((CHAR8 *)TmpChunk->Data, WAVE_CHUNK_ID, RIFF_CHUNK_ID_SIZE) != 0))
  {
    return EFI_UNSUPPORTED;
  }
 
  WaveFormat = NULL;
  DataChunk  = NULL;
  BufferPtr  = Buffer + sizeof (RIFF_CHUNK) + RIFF_CHUNK_ID_SIZE;
  BufferEnd  = Buffer + BufferSize;
 
  //
  // Find format and data chunks.
  //
  while (BufferEnd - BufferPtr >= sizeof (RIFF_CHUNK)) {
    TmpChunk = (RIFF_CHUNK *)BufferPtr;
 
    //
    // If chunk size exceeds file size, abort.
    //
    if ((UINT64)TmpChunk->Size + sizeof (RIFF_CHUNK) > (UINTN)(BufferEnd - BufferPtr)) {
      return EFI_INVALID_PARAMETER;
    }
 
    if (AsciiStrnCmp (TmpChunk->Id, WAVE_FORMAT_CHUNK_ID, RIFF_CHUNK_ID_SIZE) == 0) {
      if (TmpChunk->Size < sizeof (WAVE_FORMAT_DATA)) {
        return EFI_INVALID_PARAMETER;
      }
 
      WaveFormat = (WAVE_FORMAT_DATA *)TmpChunk->Data;
    } else if (AsciiStrnCmp (TmpChunk->Id, WAVE_DATA_CHUNK_ID, RIFF_CHUNK_ID_SIZE) == 0) {
      DataChunk = TmpChunk;
    }
 
    if ((WaveFormat != NULL) && (DataChunk != NULL)) {
      break;
    }
 
    BufferPtr += TmpChunk->Size + sizeof (RIFF_CHUNK);
  }
 
  if ((WaveFormat == NULL) || (DataChunk == NULL)) {
    return EFI_UNSUPPORTED;
  }
 
  *RawBuffer     = DataChunk->Data;
  *RawBufferSize = DataChunk->Size;
 
  switch (WaveFormat->SamplesPerSec) {
    case 8000:
      *Frequency = EfiAudioIoFreq8kHz;
      break;
    case 11000:
      *Frequency = EfiAudioIoFreq11kHz;
      break;
    case 16000:
      *Frequency = EfiAudioIoFreq16kHz;
      break;
    case 22050:
      *Frequency = EfiAudioIoFreq22kHz;
      break;
    case 32000:
      *Frequency = EfiAudioIoFreq32kHz;
      break;
    case 44100:
      *Frequency = EfiAudioIoFreq44kHz;
      break;
    case 48000:
      *Frequency = EfiAudioIoFreq48kHz;
      break;
    case 88000:
      *Frequency = EfiAudioIoFreq88kHz;
      break;
    case 96000:
      *Frequency = EfiAudioIoFreq96kHz;
      break;
    case 192000:
      *Frequency = EfiAudioIoFreq192kHz;
      break;
    default:
      return EFI_UNSUPPORTED;
  }
 
  switch (WaveFormat->BitsPerSample) {
    case 8:
      *Bits = EfiAudioIoBits8;
      break;
    case 16:
      *Bits = EfiAudioIoBits16;
      break;
    case 20:
      *Bits = EfiAudioIoBits20;
      break;
    case 24:
      *Bits = EfiAudioIoBits24;
      break;
    case 32:
      *Bits = EfiAudioIoBits32;
      break;
    default:
      return EFI_UNSUPPORTED;
  }
 
  *Channels = (UINT8)WaveFormat->Channels;
 
  return EFI_SUCCESS;
}