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-rw-r--r--src/wavfile.cpp268
1 files changed, 268 insertions, 0 deletions
diff --git a/src/wavfile.cpp b/src/wavfile.cpp
new file mode 100644
index 0000000..dbc1e13
--- /dev/null
+++ b/src/wavfile.cpp
@@ -0,0 +1,268 @@
+/* ------------------------------------------------------------------
+ * Copyright (C) 2009 Martin Storsjo
+ * Copyright (C) 2017 Matthias P. Braendli
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ * -------------------------------------------------------------------
+ */
+
+#include "wavfile.h"
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <cstdint>
+#include <stdexcept>
+
+#define TAG(a, b, c, d) (((a) << 24) | ((b) << 16) | ((c) << 8) | (d))
+
+struct wav_reader {
+ FILE *wav;
+ uint32_t data_length;
+
+ int format;
+ int sample_rate;
+ int bits_per_sample;
+ int channels;
+ int byte_rate;
+ int block_align;
+
+ int streamed;
+};
+
+static uint32_t read_tag(struct wav_reader* wr) {
+ uint32_t tag = 0;
+ tag = (tag << 8) | fgetc(wr->wav);
+ tag = (tag << 8) | fgetc(wr->wav);
+ tag = (tag << 8) | fgetc(wr->wav);
+ tag = (tag << 8) | fgetc(wr->wav);
+ return tag;
+}
+
+static uint32_t read_int32(struct wav_reader* wr) {
+ uint32_t value = 0;
+ value |= fgetc(wr->wav) << 0;
+ value |= fgetc(wr->wav) << 8;
+ value |= fgetc(wr->wav) << 16;
+ value |= fgetc(wr->wav) << 24;
+ return value;
+}
+
+static uint16_t read_int16(struct wav_reader* wr) {
+ uint16_t value = 0;
+ value |= fgetc(wr->wav) << 0;
+ value |= fgetc(wr->wav) << 8;
+ return value;
+}
+
+static void skip(FILE *f, int n) {
+ int i;
+ for (i = 0; i < n; i++)
+ fgetc(f);
+}
+
+void* wav_read_open(const char *filename) {
+ struct wav_reader* wr = (struct wav_reader*) malloc(sizeof(*wr));
+ long data_pos = 0;
+ memset(wr, 0, sizeof(*wr));
+
+ if (!strcmp(filename, "-"))
+ wr->wav = stdin;
+ else
+ wr->wav = fopen(filename, "rb");
+ if (wr->wav == NULL) {
+ free(wr);
+ return NULL;
+ }
+
+ while (1) {
+ uint32_t tag, tag2, length;
+ tag = read_tag(wr);
+ if (feof(wr->wav))
+ break;
+ length = read_int32(wr);
+ if (!length || length >= 0x7fff0000) {
+ wr->streamed = 1;
+ length = ~0;
+ }
+ if (tag != TAG('R', 'I', 'F', 'F') || length < 4) {
+ fseek(wr->wav, length, SEEK_CUR);
+ continue;
+ }
+ tag2 = read_tag(wr);
+ length -= 4;
+ if (tag2 != TAG('W', 'A', 'V', 'E')) {
+ fseek(wr->wav, length, SEEK_CUR);
+ continue;
+ }
+ // RIFF chunk found, iterate through it
+ while (length >= 8) {
+ uint32_t subtag, sublength;
+ subtag = read_tag(wr);
+ if (feof(wr->wav))
+ break;
+ sublength = read_int32(wr);
+ length -= 8;
+ if (length < sublength)
+ break;
+ if (subtag == TAG('f', 'm', 't', ' ')) {
+ if (sublength < 16) {
+ // Insufficient data for 'fmt '
+ break;
+ }
+ wr->format = read_int16(wr);
+ wr->channels = read_int16(wr);
+ wr->sample_rate = read_int32(wr);
+ wr->byte_rate = read_int32(wr);
+ wr->block_align = read_int16(wr);
+ wr->bits_per_sample = read_int16(wr);
+ if (wr->format == 0xfffe) {
+ if (sublength < 28) {
+ // Insufficient data for waveformatex
+ break;
+ }
+ skip(wr->wav, 8);
+ wr->format = read_int32(wr);
+ skip(wr->wav, sublength - 28);
+ } else {
+ skip(wr->wav, sublength - 16);
+ }
+ } else if (subtag == TAG('d', 'a', 't', 'a')) {
+ data_pos = ftell(wr->wav);
+ wr->data_length = sublength;
+ if (!wr->data_length || wr->streamed) {
+ wr->streamed = 1;
+ return wr;
+ }
+ fseek(wr->wav, sublength, SEEK_CUR);
+ } else {
+ skip(wr->wav, sublength);
+ }
+ length -= sublength;
+ }
+ if (length > 0) {
+ // Bad chunk?
+ fseek(wr->wav, length, SEEK_CUR);
+ }
+ }
+ fseek(wr->wav, data_pos, SEEK_SET);
+ return wr;
+}
+
+void wav_read_close(void* obj) {
+ struct wav_reader* wr = (struct wav_reader*) obj;
+ if (wr->wav != stdin)
+ fclose(wr->wav);
+ free(wr);
+}
+
+int wav_get_header(void* obj, int* format, int* channels, int* sample_rate, int* bits_per_sample, unsigned int* data_length) {
+ struct wav_reader* wr = (struct wav_reader*) obj;
+ if (format)
+ *format = wr->format;
+ if (channels)
+ *channels = wr->channels;
+ if (sample_rate)
+ *sample_rate = wr->sample_rate;
+ if (bits_per_sample)
+ *bits_per_sample = wr->bits_per_sample;
+ if (data_length)
+ *data_length = wr->data_length;
+ return wr->format && wr->sample_rate;
+}
+
+int wav_read_data(void* obj, unsigned char* data, unsigned int length) {
+ struct wav_reader* wr = (struct wav_reader*) obj;
+ int n;
+ if (wr->wav == NULL)
+ return -1;
+ if (length > wr->data_length && !wr->streamed)
+ length = wr->data_length;
+ n = fread(data, 1, length, wr->wav);
+ wr->data_length -= length;
+ return n;
+}
+
+//============== WAV writer functions
+
+struct wavfile_header {
+ char riff_tag[4];
+ int riff_length;
+ char wave_tag[4];
+ char fmt_tag[4];
+ int fmt_length;
+ short audio_format;
+ short num_channels;
+ int sample_rate;
+ int byte_rate;
+ short block_align;
+ short bits_per_sample;
+ char data_tag[4];
+ int data_length;
+};
+
+WavWriter::WavWriter(const char *filename, int rate)
+{
+ struct wavfile_header header;
+
+ int samples_per_second = rate;
+ int bits_per_sample = 16;
+
+ strncpy(header.riff_tag,"RIFF",4);
+ strncpy(header.wave_tag,"WAVE",4);
+ strncpy(header.fmt_tag,"fmt ",4);
+ strncpy(header.data_tag,"data",4);
+
+ header.riff_length = 0;
+ header.fmt_length = 16;
+ header.audio_format = 1;
+ header.num_channels = 2;
+ header.sample_rate = samples_per_second;
+ header.byte_rate = samples_per_second*(bits_per_sample/8);
+ header.block_align = bits_per_sample/8;
+ header.bits_per_sample = bits_per_sample;
+ header.data_length = 0;
+
+ m_fd = fopen(filename, "w+");
+ if (not m_fd) {
+ throw std::runtime_error("Could not open wav file");
+ }
+
+ fwrite(&header,sizeof(header),1,m_fd);
+
+ fflush(m_fd);
+}
+
+WavWriter::~WavWriter()
+{
+ // The wav file header contains the full file size, we must
+ // write this at the end
+
+ int file_length = ftell(m_fd);
+
+ int data_length = file_length - sizeof(struct wavfile_header);
+ fseek(m_fd,sizeof(struct wavfile_header) - sizeof(int),SEEK_SET);
+ fwrite(&data_length,sizeof(data_length),1,m_fd);
+
+ int riff_length = file_length - 8;
+ fseek(m_fd,4,SEEK_SET);
+ fwrite(&riff_length,sizeof(riff_length),1,m_fd);
+
+ fclose(m_fd);
+}
+
+void WavWriter::write_data(short data[], int length)
+{
+ fwrite(data,sizeof(short),length,m_fd);
+}
+
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