static int encode_audio(struct mgcp_process_rtp_state *state,
uint8_t *dst, size_t buf_size, size_t max_samples)
{
int nbytes = 0;
size_t nsamples = 0;
/* Encode samples into dst */
while (nsamples + state->dst_samples_per_frame <= max_samples) {
if (nbytes + state->dst_frame_size > buf_size) {
if (nbytes > 0)
break;
/* Not even one frame fits into the buffer */
LOGP(DMGCP, LOGL_INFO,
"Encoding (RTP) buffer too small: %d > %d.\n",
nbytes + state->dst_frame_size, buf_size);
return -ENOSPC;
}
switch (state->dst_fmt) {
case AF_GSM:
gsm_encode(state->dst.gsm_handle,
state->samples + state->sample_offs, dst);
break;
#ifdef HAVE_BCG729
case AF_G729:
bcg729Encoder(state->dst.g729_enc,
state->samples + state->sample_offs, dst);
break;
#endif
case AF_PCMU:
ulaw_encode(state->samples + state->sample_offs, dst,
state->src_samples_per_frame);
break;
case AF_PCMA:
alaw_encode(state->samples + state->sample_offs, dst,
state->src_samples_per_frame);
break;
case AF_S16:
memmove(dst, state->samples + state->sample_offs,
state->dst_frame_size);
break;
case AF_L16:
l16_encode(state->samples + state->sample_offs, dst,
state->src_samples_per_frame);
break;
default:
break;
}
dst += state->dst_frame_size;
nbytes += state->dst_frame_size;
state->sample_offs += state->dst_samples_per_frame;
nsamples += state->dst_samples_per_frame;
}
state->sample_cnt -= nsamples;
return nbytes;
}
void wav2c(FILE *in, FILE *out, FILE *outh)
{
uint32_t header[5];
int16_t format, channels, bits;
uint32_t rate;
uint32_t i, length, padlength=0, arraylen;
int32_t audio=0;
// read the WAV file's header
for (i=0; i<5; i++) {
header[i] = read_uint32(in);
}
if (header[0] != 0x46464952 || header[2] != 0x45564157
|| header[3] != 0x20746D66 || header[4] != 0x00000010) {
die("error in format of file %s", filename);
}
// read the audio format parameters
format = read_int16(in);
channels = read_int16(in);
rate = read_uint32(in);
read_uint32(in); // ignore byterate
read_int16(in); // ignore blockalign
bits = read_int16(in);
//printf("format: %d, channels: %d, rate: %d, bits %d\n", format, channels, rate, bits);
if (format != 1)
die("file %s is compressed, only uncompressed supported", filename);
if (rate != 44100 && rate != 22050 && rate != 11025 /*&& rate != 8000*/ )
die("sample rate %d in %s is unsupported\n"
"Only 44100, 22050, 11025 work", rate, filename);
if (channels != 1 && channels != 2)
die("file %s has %d channels, but only 1 & 2 are supported", filename, channels);
if (bits != 16)
die("file %s has %d bit format, but only 16 is supported", filename, bits);
// read the data header, skip non-audio data
while (1) {
header[0] = read_uint32(in);
length = read_uint32(in);
if (header[0] == 0x61746164) break; // beginning of actual audio data
// skip over non-audio data
for (i=0; i < length; i++) {
read_uint8(in);
}
}
// the length must be a multiple of the data size
if (channels == 2) {
if (length % 4) die("file %s data length is not a multiple of 4", filename);
length = length / 4;
}
if (channels == 1) {
if (length % 1) die("file %s data length is not a multiple of 2", filename);
length = length / 2;
}
if (length > 0xFFFFFF) die("file %s data length is too long", filename);
bcount = 0;
// AudioPlayMemory requires padding to 2.9 ms boundary (128 samples @ 44100)
if (rate == 44100) {
padlength = padding(length, 128);
format = 1;
} else if (rate == 22050) {
padlength = padding(length, 64);
format = 2;
} else if (rate == 11025) {
padlength = padding(length, 32);
format = 3;
}
if (pcm_mode) {
arraylen = ((length + padlength) * 2 + 3) / 4 + 1;
format |= 0x80;
} else {
arraylen = (length + padlength + 3) / 4 + 1;
}
total_length += arraylen;
// output a minimal header, just the length, #bits and sample rate
fprintf(outh, "extern const unsigned int AudioSample%s[%d];\n", samplename, arraylen);
fprintf(out, "// Converted from %s, using %d Hz, %s encoding\n", filename, rate,
(pcm_mode ? "16 bit PCM" : "u-law"));
fprintf(out, "const unsigned int AudioSample%s[%d] = {\n", samplename, arraylen);
fprintf(out, "0x%08X,", length | (format << 24));
wcount = 1;
// finally, read the audio data
while (length > 0) {
if (channels == 1) {
audio = read_int16(in);
} else {
audio = read_int16(in);
audio += read_int16(in);
audio /= 2;
}
if (pcm_mode) {
print_byte(out, audio);
print_byte(out, audio >> 8);
} else {
print_byte(out, ulaw_encode(audio));
}
length--;
}