mpv/libmpcodecs/ad_hwac3.c

106 lines
2.4 KiB
C

// Reference: DOCS/tech/hwac3.txt !!!!!
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "config.h"
#include "mp_msg.h"
#include "help_mp.h"
#include "ad_internal.h"
#include "../liba52/a52.h"
extern int a52_fillbuff(sh_audio_t *sh_audio);
static ad_info_t info =
{
"AC3 through SPDIF",
"hwac3",
AFM_HWAC3,
"Nick Kurshev",
"???",
""
};
LIBAD_EXTERN(hwac3)
static int preinit(sh_audio_t *sh)
{
/* Dolby AC3 audio: */
sh->audio_out_minsize=4*256*6;
sh->audio_in_minsize=3840;
sh->channels=2;
sh->sample_format=AFMT_AC3;
return 1;
}
static int init(sh_audio_t *sh_audio)
{
/* Dolby AC3 passthrough:*/
sample_t *a52_samples=a52_init(0);
if (a52_samples == NULL) {
mp_msg(MSGT_DECAUDIO,MSGL_ERR,"A52 init failed\n");
return 0;
}
if(a52_fillbuff(sh_audio)<0) {
mp_msg(MSGT_DECAUDIO,MSGL_ERR,"A52 sync failed\n");
return 0;
}
/*
sh_audio->samplerate=ai.samplerate; // SET by a52_fillbuff()
sh_audio->samplesize=ai.framesize;
sh_audio->i_bps=ai.bitrate*(1000/8); // SET by a52_fillbuff()
sh_audio->ac3_frame=malloc(6144);
sh_audio->o_bps=sh_audio->i_bps; // XXX FIXME!!! XXX
o_bps is calculated from samplesize*channels*samplerate
a single ac3 frame is always translated to 6144 byte packet. (zero padding)*/
sh_audio->channels=2;
sh_audio->samplesize=2; /* 2*2*(6*256) = 6144 (very TRICKY!)*/
return 1;
}
static void uninit(sh_audio_t *sh)
{
}
static int control(sh_audio_t *sh,int cmd,void* arg, ...)
{
switch(cmd)
{
case ADCTRL_SKIP_FRAME:
a52_fillbuff(sh); break; // skip AC3 frame
return CONTROL_TRUE;
}
return CONTROL_UNKNOWN;
}
static int decode_audio(sh_audio_t *sh_audio,unsigned char *buf,int minlen,int maxlen)
{
int len=-1;
if(!sh_audio->a_in_buffer_len)
if((len=a52_fillbuff(sh_audio))<=0) return len; /*EOF*/
sh_audio->a_in_buffer_len=0;
// int ac3_iec958_build_burst(int length, int data_type, int big_endian, unsigned char * data, unsigned char * out)
// len = ac3_iec958_build_burst(len, 0x01, 1, sh_audio->a_in_buffer, buf);
buf[0] = 0x72;
buf[1] = 0xF8;
buf[2] = 0x1F;
buf[3] = 0x4E;
buf[4] = 0x01; //(length) ? data_type : 0; /* & 0x1F; */
buf[5] = 0x00;
buf[6] = (len << 3) & 0xFF;
buf[7] = (len >> 5) & 0xFF;
swab(sh_audio->a_in_buffer, buf + 8, len);
//memcpy(buf + 8, sh_audio->a_in_buffer, len);
memset(buf + 8 + len, 0, 6144 - 8 - len);
return 6144;
}