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move mix level tables from parser to decoder. have parser read bitstream value instead of using an index to a table in the decoder.

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Originally committed as revision 13696 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2008-06-07 22:30:09 +00:00
parent caf0fbc889
commit 30f71adc46
2 changed files with 18 additions and 18 deletions
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20
libavcodec/ac3_parser.c
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@ -33,18 +33,6 @@ static const uint8_t eac3_blocks[4] = {
1, 2, 3, 6
};
/**
* Table for center mix levels
* reference: Section 5.4.2.4 cmixlev
*/
static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
/**
* Table for surround mix levels
* reference: Section 5.4.2.5 surmixlev
*/
static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
@ -64,8 +52,8 @@ int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
hdr->num_blocks = 6;
/* set default mix levels */
hdr->center_mix_level = 3; // -4.5dB
hdr->surround_mix_level = 4; // -6.0dB
hdr->center_mix_level = 1; // -4.5dB
hdr->surround_mix_level = 1; // -6.0dB
if(hdr->bitstream_id <= 10) {
/* Normal AC-3 */
@ -87,9 +75,9 @@ int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
skip_bits(gbc, 2); // skip dsurmod
} else {
if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO)
hdr->center_mix_level = center_levels[get_bits(gbc, 2)];
hdr->center_mix_level = get_bits(gbc, 2);
if(hdr->channel_mode & 4)
hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)];
hdr->surround_mix_level = get_bits(gbc, 2);
}
hdr->lfe_on = get_bits1(gbc);

16
libavcodec/ac3dec.c
View File

@ -94,6 +94,18 @@ static const float gain_levels[9] = {
LEVEL_MINUS_9DB
};
/**
* Table for center mix levels
* reference: Section 5.4.2.4 cmixlev
*/
static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
/**
* Table for surround mix levels
* reference: Section 5.4.2.5 surmixlev
*/
static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
/**
* Table for default stereo downmixing coefficients
* reference: Section 7.8.2 Downmixing Into Two Channels
@ -383,8 +395,8 @@ static int ac3_parse_header(AC3DecodeContext *s)
static void set_downmix_coeffs(AC3DecodeContext *s)
{
int i;
float cmix = gain_levels[s->center_mix_level];
float smix = gain_levels[s->surround_mix_level];
float cmix = gain_levels[center_levels[s->center_mix_level]];
float smix = gain_levels[surround_levels[s->surround_mix_level]];
for(i=0; i<s->fbw_channels; i++) {
s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];