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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 "audio.h"
cMarkAdAudio::cMarkAdAudio(MarkAdContext *maContext)
{
macontext=maContext;
mark.Comment=NULL;
mark.Position=0;
mark.Type=0;
channels=0;
#if 0
lastiframe_gain=-ANALYZEFRAMES;
#endif
lastiframe_silence=-1;
}
cMarkAdAudio::~cMarkAdAudio()
{
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()
{
if (!macontext->Audio.Data.Valid) return false;
if (lastiframe_silence==lastiframe) return false; // we already detected silence for this frame
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)
{
lastiframe_silence=lastiframe;
return true;
}
}
else
{
lowvalcount=0;
}
}
return false;
}
#if 0
bool cMarkAdAudio::AnalyzeGain()
{
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 ((lastiframe-lastiframe_gain)>ANALYZEFRAMES)
{
if (lastiframe_gain>0)
{
double dgain,gain = audiogain.GetGain();
dgain=gain-lastgain;
printf("%05i %+.2f db %+.2f db\n",lastiframe_gain,gain,lastgain);
lastgain=gain;
}
audiogain.Init(macontext->Audio.Info.SampleRate);
lastiframe_gain=lastiframe;
}
if (audiogain.AnalyzeSamples(left,right,samples,2)!=GAIN_ANALYSIS_OK)
{
lastiframe_gain=-ANALYZEFRAMES;
}
return true;
}
#endif
bool cMarkAdAudio::ChannelChange(int a, int b)
{
if ((a==0) || (b==0)) return false;
if (a!=b) return true;
return false;
}
MarkAdMark *cMarkAdAudio::Process(int LastIFrame)
{
ResetMark();
if (!LastIFrame) return NULL;
lastiframe=LastIFrame;
#if 0
AnalyzeGain();
#endif
if (macontext->Audio.Options.AudioSilenceDetection)
{
if (SilenceDetection())
{
char *buf=NULL;
if (asprintf(&buf,"audio channel silence detecion (%i)",lastiframe)!=-1)
{
AddMark(MT_SILENCECHANGE,lastiframe,buf);
free(buf);
}
}
}
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,lastiframe)!=-1)
{
if (macontext->Audio.Info.Channels>2)
{
AddMark(MT_CHANNELSTART,lastiframe,buf);
}
else
{
AddMark(MT_CHANNELSTOP,lastiframe,buf);
}
free(buf);
}
}
channels=macontext->Audio.Info.Channels;
return &mark;
}
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