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/*
* audio.cpp: A program for the Video Disk Recorder
*
* See the README file for copyright information and how to reach the author.
*
* $Id$
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
extern "C"
{
#include "debug.h"
}
#include "audio.h"
cMarkAdAudio::cMarkAdAudio(MarkAdContext *maContext)
{
macontext=maContext;
mark.Comment=NULL;
mark.Position=0;
mark.Type=0;
result.CommentBefore=NULL;
result.CommentAfter=NULL;
Clear();
}
cMarkAdAudio::~cMarkAdAudio()
{
Clear();
ResetMark();
}
void cMarkAdAudio::ResetMark()
{
if (mark.Comment) free(mark.Comment);
mark.Comment=NULL;
mark.Position=0;
mark.Type=0;
}
bool cMarkAdAudio::AddMark(int Type, int Position, const char *Comment)
{
if (!Comment) return false;
if (mark.Comment)
{
int oldlen=strlen(mark.Comment);
mark.Comment=(char *) realloc(mark.Comment,oldlen+10+strlen(Comment));
if (!mark.Comment)
{
mark.Position=0;
return false;
}
strcat(mark.Comment," [");
strcat(mark.Comment,Comment);
strcat(mark.Comment,"]");
}
else
{
mark.Comment=strdup(Comment);
}
mark.Position=Position;
mark.Type=Type;
return true;
}
bool cMarkAdAudio::SilenceDetection(int FrameNumber)
{
// function taken from noad
if (!FrameNumber) return false;
if (!macontext->Audio.Data.Valid) return false;
if (lastframe_silence==FrameNumber) return false; // we already detected silence for this frame
if (lastframe_silence==-1)
{
// ignore first detection
lastframe_silence=FrameNumber;
return false;
}
int samples=macontext->Audio.Data.SampleBufLen/
sizeof(*macontext->Audio.Data.SampleBuf)/
macontext->Audio.Info.Channels;
short left,right;
int lowvalcount=0;
for (int i=0; i<samples; i++)
{
left=macontext->Audio.Data.SampleBuf[0+(i*2)];
right=macontext->Audio.Data.SampleBuf[1+(i*2)];
if ((abs(left)+abs(right))<CUT_VAL)
{
lowvalcount++;
if (lowvalcount>MIN_LOWVALS)
{
lastframe_silence=FrameNumber;
}
}
else
{
if (lastframe_silence==FrameNumber)
{
return true;
}
lowvalcount=0;
}
}
return false;
}
bool cMarkAdAudio::AnalyzeGain(int FrameNumber)
{
if (!macontext->Audio.Data.Valid) return false;
int samples=macontext->Audio.Data.SampleBufLen/
sizeof(*macontext->Audio.Data.SampleBuf)/
macontext->Audio.Info.Channels;
double left[samples];
double right[samples];
for (int i=0; i<samples; i++)
{
left[i]=macontext->Audio.Data.SampleBuf[0+(i*2)];
right[i]=macontext->Audio.Data.SampleBuf[1+(i*2)];
}
if (FrameNumber!=lastframe_gain)
{
if ((lastframe_gain>0) && (audiogain.AnalyzedSamples()>=(3*samples)))
{
double gain = audiogain.GetGain();
printf("%05i %+.2f db\n",lastframe_gain,gain);
}
audiogain.Init(macontext->Audio.Info.SampleRate);
lastframe_gain=-1;
}
if (audiogain.AnalyzeSamples(left,right,samples,2)!=GAIN_ANALYSIS_OK)
{
lastframe_gain=-1;
return false;
}
else
{
lastframe_gain=FrameNumber;
}
return true;
}
void cMarkAdAudio::Clear()
{
channels=0;
lastframe_gain=-1;
lastframe_silence=-1;
if (result.CommentBefore) free(result.CommentBefore);
if (result.CommentAfter) free(result.CommentAfter);
memset(&result,0,sizeof(result));
}
bool cMarkAdAudio::ChannelChange(int a, int b)
{
if ((a==0) || (b==0)) return false;
if (a!=b) return true;
return false;
}
MarkAdPos *cMarkAdAudio::Process2ndPass(int FrameNumber)
{
if (!FrameNumber) return NULL;
#if 0
if (SilenceDetection(FrameNumber))
{
if (result.CommentBefore) free(result.CommentBefore);
if (asprintf(&result.CommentBefore,"audio silence detection (%i)",FrameNumber)==-1)
{
result.CommentBefore=NULL;
}
result.FrameNumberBefore=FrameNumber;
return &result;
}
#endif
return NULL;
}
MarkAdMark *cMarkAdAudio::Process(int FrameNumber, int FrameNumberNext)
{
if ((!FrameNumber) || (!FrameNumberNext)) return NULL;
ResetMark();
if (ChannelChange(macontext->Audio.Info.Channels,channels))
{
char *buf=NULL;
if (asprintf(&buf,"audio channel change from %i to %i (%i)", channels,
macontext->Audio.Info.Channels,
(macontext->Audio.Info.Channels>2) ? FrameNumberNext :
framelast)!=-1)
{
if (macontext->Audio.Info.Channels>2)
{
AddMark(MT_CHANNELSTART,FrameNumberNext,buf);
}
else
{
AddMark(MT_CHANNELSTOP,framelast,buf);
}
free(buf);
}
}
channels=macontext->Audio.Info.Channels;
framelast=FrameNumberNext;
return &mark;
}
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