1 files changed, 53 insertions, 27 deletions

diff --git a/webrtc/common_audio/wav_header.h b/webrtc/common_audio/wav_header.h
index 1a0fd7c..2cccd7d 100644
--- a/webrtc/common_audio/wav_header.h
+++ b/webrtc/common_audio/wav_header.h
@@ -8,57 +8,83 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
-#define WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
+#ifndef COMMON_AUDIO_WAV_HEADER_H_
+#define COMMON_AUDIO_WAV_HEADER_H_
 
 #include <stddef.h>
 #include <stdint.h>
+#include <algorithm>
 
-namespace webrtc {
+#include "rtc_base/checks.h"
 
-static const size_t kWavHeaderSize = 44;
+namespace webrtc {
 
-class ReadableWav {
+// Interface providing header reading functionality.
+class WavHeaderReader {
  public:
   // Returns the number of bytes read.
-  size_t virtual Read(void* buf, size_t num_bytes) = 0;
-  virtual ~ReadableWav() {}
+  virtual size_t Read(void* buf, size_t num_bytes) = 0;
+  virtual bool SeekForward(uint32_t num_bytes) = 0;
+  virtual ~WavHeaderReader() = default;
+  virtual int64_t GetPosition() = 0;
 };
 
-enum WavFormat {
-  kWavFormatPcm   = 1,  // PCM, each sample of size bytes_per_sample
-  kWavFormatALaw  = 6,  // 8-bit ITU-T G.711 A-law
-  kWavFormatMuLaw = 7,  // 8-bit ITU-T G.711 mu-law
+// Possible WAV formats.
+enum class WavFormat {
+  kWavFormatPcm = 1,        // PCM, each sample of size bytes_per_sample.
+  kWavFormatIeeeFloat = 3,  // IEEE float.
+  kWavFormatALaw = 6,       // 8-bit ITU-T G.711 A-law.
+  kWavFormatMuLaw = 7,      // 8-bit ITU-T G.711 mu-law.
 };
 
+// Header sizes for supported WAV formats.
+constexpr size_t kPcmWavHeaderSize = 44;
+constexpr size_t kIeeeFloatWavHeaderSize = 58;
+
+// Returns the size of the WAV header for the specified format.
+constexpr size_t WavHeaderSize(WavFormat format) {
+  if (format == WavFormat::kWavFormatPcm) {
+    return kPcmWavHeaderSize;
+  }
+  RTC_CHECK_EQ(format, WavFormat::kWavFormatIeeeFloat);
+  return kIeeeFloatWavHeaderSize;
+}
+
+// Returns the maximum size of the supported WAV formats.
+constexpr size_t MaxWavHeaderSize() {
+  return std::max(WavHeaderSize(WavFormat::kWavFormatPcm),
+                  WavHeaderSize(WavFormat::kWavFormatIeeeFloat));
+}
+
 // Return true if the given parameters will make a well-formed WAV header.
-bool CheckWavParameters(int num_channels,
+bool CheckWavParameters(size_t num_channels,
                         int sample_rate,
                         WavFormat format,
-                        int bytes_per_sample,
-                        uint32_t num_samples);
+                        size_t num_samples);
 
 // Write a kWavHeaderSize bytes long WAV header to buf. The payload that
 // follows the header is supposed to have the specified number of interleaved
 // channels and contain the specified total number of samples of the specified
-// type. CHECKs the input parameters for validity.
-void WriteWavHeader(uint8_t* buf,
-                    int num_channels,
+// type. The size of the header is returned in header_size. CHECKs the input
+// parameters for validity.
+void WriteWavHeader(size_t num_channels,
                     int sample_rate,
                     WavFormat format,
-                    int bytes_per_sample,
-                    uint32_t num_samples);
+                    size_t num_samples,
+                    uint8_t* buf,
+                    size_t* header_size);
 
-// Read a WAV header from an implemented ReadableWav and parse the values into
-// the provided output parameters. ReadableWav is used because the header can
-// be variably sized. Returns false if the header is invalid.
-bool ReadWavHeader(ReadableWav* readable,
-                   int* num_channels,
+// Read a WAV header from an implemented WavHeaderReader and parse the values
+// into the provided output parameters. WavHeaderReader is used because the
+// header can be variably sized. Returns false if the header is invalid.
+bool ReadWavHeader(WavHeaderReader* readable,
+                   size_t* num_channels,
                    int* sample_rate,
                    WavFormat* format,
-                   int* bytes_per_sample,
-                   uint32_t* num_samples);
+                   size_t* bytes_per_sample,
+                   size_t* num_samples,
+                   int64_t* data_start_pos);
 
 }  // namespace webrtc
 
-#endif  // WEBRTC_COMMON_AUDIO_WAV_HEADER_H_
+#endif  // COMMON_AUDIO_WAV_HEADER_H_