Skip to content

V
vlc-2-2
Commit 39e48a79 authored by Rafaël Carré's avatar Rafaël Carré
Browse files
Options

flac packetizer: simplify header parsing

parent 88bcfa08
Show whitespace changes
Inline Side-by-side
Showing with 81 additions and 152 deletions
modules/packetizer/flac.c
View file @ 39e48a79
......@@ -247,9 +247,6 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
unsigned int * pi_bits_per_sample)
{
decoder_sys_t *p_sys = p_dec->p_sys;
int i_header, i_temp, i_read;
unsigned i_blocksize = 0;
int i_blocksize_hint = 0, i_sample_rate_hint = 0;
/* Check syncword */
if (p_buf[0] != 0xFF || (p_buf[1] & 0xFE) != 0xF8)
......@@ -260,184 +257,111 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
return 0;
/* Find blocksize (framelength) */
switch (i_temp = p_buf[2] >> 4) {
case 0:
int blocksize_hint = 0;
unsigned blocksize = p_buf[2] >> 4;
if (blocksize >= 8) {
blocksize = 256 << (blocksize - 8);
} else if (blocksize == 0) { /* value 0 is reserved */
if (p_sys->b_stream_info &&
p_sys->stream_info.min_blocksize == p_sys->stream_info.max_blocksize)
i_blocksize = p_sys->stream_info.min_blocksize;
else return 0; /* We can't do anything with this */
break;
case 1:
i_blocksize = 192;
break;
case 2:
case 3:
case 4:
case 5:
i_blocksize = 576 << (i_temp - 2);
break;
case 6:
case 7:
i_blocksize_hint = i_temp;
break;
case 8:
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
i_blocksize = 256 << (i_temp - 8);
break;
blocksize = p_sys->stream_info.min_blocksize;
else
return 0; /* We can't do anything with this */
} else if (blocksize == 1) {
blocksize = 192;
} else if (blocksize == 6 || blocksize == 7) {
blocksize_hint = blocksize;
blocksize = 0;
} else /* 2, 3, 4, 5 */ {
blocksize = 576 << (blocksize - 2);
}
if (p_sys->b_stream_info &&
(i_blocksize < p_sys->stream_info.min_blocksize ||
i_blocksize > p_sys->stream_info.max_blocksize))
if (p_sys->b_stream_info)
if (blocksize < p_sys->stream_info.min_blocksize ||
blocksize > p_sys->stream_info.max_blocksize)
return 0;
/* Find samplerate */
switch (i_temp = p_buf[2] & 0x0f) {
case 0:
int samplerate_hint = p_buf[2] & 0xf;;
unsigned int samplerate;
if (samplerate_hint == 0) {
if (p_sys->b_stream_info)
*pi_sample_rate = p_sys->stream_info.sample_rate;
else return 0; /* We can't do anything with this */
break;
case 1:
*pi_sample_rate = 88200;
break;
case 2:
*pi_sample_rate = 176400;
break;
case 3:
*pi_sample_rate = 192000;
break;
case 4:
*pi_sample_rate = 8000;
break;
case 5:
*pi_sample_rate = 16000;
break;
case 6:
*pi_sample_rate = 22050;
break;
case 7:
*pi_sample_rate = 24000;
break;
case 8:
*pi_sample_rate = 32000;
break;
case 9:
*pi_sample_rate = 44100;
break;
case 10:
*pi_sample_rate = 48000;
break;
case 11:
*pi_sample_rate = 96000;
break;
case 12:
case 13:
case 14:
i_sample_rate_hint = i_temp;
break;
case 15:
return 0;
samplerate = p_sys->stream_info.sample_rate;
else
return 0; /* We can't do anything with this */
} else if (samplerate_hint == 15) {
return 0; /* invalid */
} else if (samplerate_hint < 12) {
static const int16_t flac_samplerate[12] = {
0, 8820, 17640, 19200,
800, 1600, 2205, 2400,
3200, 4410, 4800, 9600,
};
samplerate = flac_samplerate[samplerate_hint] * 10;
} else {
samplerate = 0; /* at end of header */
}
/* Find channels */
i_temp = (unsigned)(p_buf[3] >> 4);
if (i_temp & 8) {
if ((i_temp & 7) >= 3)
unsigned channels = p_buf[3] >> 4;
if (channels >= 8) {
if (channels >= 11) /* reserved */
return 0;
*pi_channels = 2;
channels = 2;
} else
*pi_channels = i_temp + 1;
channels++;
/* Find bits per sample */
switch (i_temp = (unsigned)(p_buf[3] & 0x0e) >> 1) {
case 0:
static const int8_t flac_bits_per_sample[8] = {
0, 8, 12, -1, 16, 20, 24, -1
};
int bits_per_sample = flac_bits_per_sample[(p_buf[3] & 0x0e) >> 1];
if (bits_per_sample == 0) {
if (p_sys->b_stream_info)
*pi_bits_per_sample = p_sys->stream_info.bits_per_sample;
bits_per_sample = p_sys->stream_info.bits_per_sample;
else
return 0;
break;
case 1:
*pi_bits_per_sample = 8;
break;
case 2:
*pi_bits_per_sample = 12;
break;
case 4:
*pi_bits_per_sample = 16;
break;
} else if (bits_per_sample < 0)
return 0;
case 5:
*pi_bits_per_sample = 20;
break;
case 6:
*pi_bits_per_sample = 24;
break;
case 3:
case 7:
/* reserved for future use */
if (p_buf[3] & 0x01)
return 0;
break;
}
/* Zero padding bit */
if (p_buf[3] & 0x01) return 0;
/* End of fixed size header */
i_header = 4;
int i_header = 4;
/* Check Sample/Frame number */
int i_read;
if (read_utf8(&p_buf[i_header++], &i_read) == INT64_C(0xffffffffffffffff))
return 0;
i_header += i_read;
/* Read blocksize */
if (i_blocksize_hint) {
int i_val1 = p_buf[i_header++];
if (i_blocksize_hint == 7) {
int i_val2 = p_buf[i_header++];
i_val1 = (i_val1 << 8) | i_val2;
if (blocksize_hint) {
blocksize = p_buf[i_header++];
if (blocksize_hint == 7) {
blocksize <<= 8;
blocksize |= p_buf[i_header++];
}
i_blocksize = i_val1 + 1;
blocksize++;
}
/* Read sample rate */
if (i_sample_rate_hint) {
int i_val1 = p_buf[i_header++];
if (i_sample_rate_hint != 12) {
int i_val2 = p_buf[i_header++];
i_val1 = (i_val1 << 8) | i_val2;
if (samplerate == 0) {
samplerate = p_buf[i_header++];
if (samplerate_hint != 12) { /* 16 bits */
samplerate <<= 8;
samplerate |= p_buf[i_header++];
}
if (i_sample_rate_hint == 12) *pi_sample_rate = i_val1 * 1000;
else if (i_sample_rate_hint == 13) *pi_sample_rate = i_val1;
else *pi_sample_rate = i_val1 * 10;
if (samplerate_hint == 12)
samplerate *= 1000;
else if (samplerate_hint == 14)
samplerate *= 10;
}
/* Check the CRC-8 byte */
......@@ -446,15 +370,20 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
/* Sanity check using stream info header when possible */
if (p_sys->b_stream_info) {
if (i_blocksize < p_sys->stream_info.min_blocksize ||
i_blocksize > p_sys->stream_info.max_blocksize)
if (blocksize < p_sys->stream_info.min_blocksize ||
blocksize > p_sys->stream_info.max_blocksize)
return 0;
if (*pi_bits_per_sample != p_sys->stream_info.bits_per_sample)
if ((unsigned)bits_per_sample != p_sys->stream_info.bits_per_sample)
return 0;
if (*pi_sample_rate != p_sys->stream_info.sample_rate)
if (samplerate != p_sys->stream_info.sample_rate)
return 0;
}
return i_blocksize;
*pi_bits_per_sample = bits_per_sample;
*pi_sample_rate = samplerate;
*pi_channels = channels;
return blocksize;
}
/* */
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment