mirror of https://git.videolan.org/git/ffmpeg.git
remove redundancy in AC-3 parser by using common tables from ac3tab.h
Originally committed as revision 8318 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles
parent
755c18ae5d
commit
050aa8b9bc
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@ -181,6 +181,11 @@ void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, uint8_t *bap,
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} while (end > bndtab[j++]);
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}
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/**
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* Initializes some tables.
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* note: This function must remain thread safe because it is called by the
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* AVParser init code.
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*/
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void ac3_common_init(void)
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{
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int i, j, k, l, v;
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@ -194,4 +199,12 @@ void ac3_common_init(void)
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l += v;
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}
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bndtab[50] = l;
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/* generate ff_ac3_frame_sizes table */
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for(i=0; i<38; i++) {
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int br = ff_ac3_bitratetab[i >> 1];
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ff_ac3_frame_sizes[i][0] = ( 2*br );
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ff_ac3_frame_sizes[i][1] = (320*br / 147) + (i & 1);
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ff_ac3_frame_sizes[i][2] = ( 3*br );
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}
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}
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@ -45,6 +45,8 @@ typedef struct AC3BitAllocParameters {
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int cplfleak, cplsleak;
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} AC3BitAllocParameters;
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extern uint16_t ff_ac3_frame_sizes[38][3];
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extern const uint8_t ff_ac3_channels[8];
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extern const uint16_t ff_ac3_freqs[3];
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extern const uint16_t ff_ac3_bitratetab[19];
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extern const int16_t ff_ac3_window[256];
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@ -611,6 +611,8 @@ static int AC3_encode_init(AVCodecContext *avctx)
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avctx->frame_size = AC3_FRAME_SIZE;
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ac3_common_init();
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/* number of channels */
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if (channels < 1 || channels > 6)
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return -1;
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@ -644,7 +646,7 @@ static int AC3_encode_init(AVCodecContext *avctx)
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return -1;
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s->bit_rate = bitrate;
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s->frmsizecod = i << 1;
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s->frame_size_min = (bitrate * 1000 * AC3_FRAME_SIZE) / (freq * 16);
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s->frame_size_min = ff_ac3_frame_sizes[s->frmsizecod][s->fscod];
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s->bits_written = 0;
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s->samples_written = 0;
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s->frame_size = s->frame_size_min;
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@ -663,8 +665,6 @@ static int AC3_encode_init(AVCodecContext *avctx)
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/* initial snr offset */
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s->csnroffst = 40;
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ac3_common_init();
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/* mdct init */
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fft_init(MDCT_NBITS - 2);
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for(i=0;i<N/4;i++) {
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@ -24,6 +24,20 @@
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* tables taken directly from AC3 spec.
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*/
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/**
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* Possible frame sizes.
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* Generated at runtime to match ATSC A/52 Table 5.18 Frame Size Code Table.
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*/
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uint16_t ff_ac3_frame_sizes[38][3];
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/**
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* Maps audio coding mode (acmod) to number of full-bandwidth channels.
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* from ATSC A/52 Table 5.8 Audio Coding Mode
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*/
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const uint8_t ff_ac3_channels[8] = {
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2, 1, 2, 3, 3, 4, 4, 5
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};
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/* possible frequencies */
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const uint16_t ff_ac3_freqs[3] = { 48000, 44100, 32000 };
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@ -22,6 +22,7 @@
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#include "avcodec.h"
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#include "mpegvideo.h"
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#include "mpegaudio.h"
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#include "ac3.h"
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#include "parser.h"
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AVCodecParser *av_first_parser = NULL;
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@ -581,60 +582,6 @@ typedef struct AC3ParseContext {
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#define AAC_HEADER_SIZE 7
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#ifdef CONFIG_AC3_PARSER
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static const int ac3_sample_rates[4] = {
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48000, 44100, 32000, 0
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};
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static const int ac3_frame_sizes[64][3] = {
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{ 64, 69, 96 },
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{ 64, 70, 96 },
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{ 80, 87, 120 },
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{ 80, 88, 120 },
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{ 96, 104, 144 },
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{ 96, 105, 144 },
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{ 112, 121, 168 },
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{ 112, 122, 168 },
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{ 128, 139, 192 },
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{ 128, 140, 192 },
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{ 160, 174, 240 },
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{ 160, 175, 240 },
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{ 192, 208, 288 },
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{ 192, 209, 288 },
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{ 224, 243, 336 },
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{ 224, 244, 336 },
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{ 256, 278, 384 },
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{ 256, 279, 384 },
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{ 320, 348, 480 },
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{ 320, 349, 480 },
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{ 384, 417, 576 },
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{ 384, 418, 576 },
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{ 448, 487, 672 },
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{ 448, 488, 672 },
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{ 512, 557, 768 },
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{ 512, 558, 768 },
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{ 640, 696, 960 },
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{ 640, 697, 960 },
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{ 768, 835, 1152 },
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{ 768, 836, 1152 },
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{ 896, 975, 1344 },
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{ 896, 976, 1344 },
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{ 1024, 1114, 1536 },
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{ 1024, 1115, 1536 },
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{ 1152, 1253, 1728 },
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{ 1152, 1254, 1728 },
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{ 1280, 1393, 1920 },
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{ 1280, 1394, 1920 },
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};
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static const int ac3_bitrates[64] = {
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32, 32, 40, 40, 48, 48, 56, 56, 64, 64, 80, 80, 96, 96, 112, 112,
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128, 128, 160, 160, 192, 192, 224, 224, 256, 256, 320, 320, 384,
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384, 448, 448, 512, 512, 576, 576, 640, 640,
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};
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static const uint8_t ac3_channels[8] = {
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2, 1, 2, 3, 3, 4, 4, 5
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};
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static const uint8_t eac3_blocks[4] = {
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1, 2, 3, 6
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@ -672,7 +619,7 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
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fscod = get_bits(&bits, 2);
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frmsizecod = get_bits(&bits, 6);
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if(fscod == 3)
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if(fscod == 3 && frmsizecod > 37)
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return 0;
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skip_bits(&bits, 5); /* bsid */
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@ -687,12 +634,12 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
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lfeon = get_bits1(&bits);
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halfratecod = FFMAX(bsid, 8) - 8;
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*sample_rate = ac3_sample_rates[fscod] >> halfratecod;
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*bit_rate = (ac3_bitrates[frmsizecod] * 1000) >> halfratecod;
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*channels = ac3_channels[acmod] + lfeon;
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*sample_rate = ff_ac3_freqs[fscod] >> halfratecod;
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*bit_rate = (ff_ac3_bitratetab[frmsizecod] * 1000) >> halfratecod;
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*channels = ff_ac3_channels[acmod] + lfeon;
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*samples = 6 * 256;
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return ac3_frame_sizes[frmsizecod][fscod] * 2;
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return ff_ac3_frame_sizes[frmsizecod][fscod] * 2;
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} else if (bsid > 10 && bsid <= 16) { /* Enhanced AC-3 */
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strmtyp = get_bits(&bits, 2);
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substreamid = get_bits(&bits, 3);
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@ -709,11 +656,11 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
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if(fscod2 == 3)
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return 0;
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*sample_rate = ac3_sample_rates[fscod2] / 2;
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*sample_rate = ff_ac3_freqs[fscod2] / 2;
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} else {
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numblkscod = get_bits(&bits, 2);
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*sample_rate = ac3_sample_rates[fscod];
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*sample_rate = ff_ac3_freqs[fscod];
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}
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acmod = get_bits(&bits, 3);
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@ -721,7 +668,7 @@ static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate,
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*samples = eac3_blocks[numblkscod] * 256;
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*bit_rate = frmsiz * (*sample_rate) * 16 / (*samples);
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*channels = ac3_channels[acmod] + lfeon;
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*channels = ff_ac3_channels[acmod] + lfeon;
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return frmsiz * 2;
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}
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@ -780,6 +727,7 @@ static int ac3_parse_init(AVCodecParserContext *s1)
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s->inbuf_ptr = s->inbuf;
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s->header_size = AC3_HEADER_SIZE;
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s->sync = ac3_sync;
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ac3_common_init();
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return 0;
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}
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#endif
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