objective c - How to create a Song Visualization in WaveFrom in MPMusicPlayer Controller -
hai folks last couple of days iam working on code create song visualization in wavefrom,,,.this code got drawing waveform avassetreader can 1 me method call when song geting played want show visualization. code have
first, generic rendering method takes pointer averaged sample data, , returns uiimage. note these samples not playable audio samples.
-(uiimage *) audioimagegraph:(sint16 *) samples normalizemax:(sint16) normalizemax samplecount:(nsinteger) samplecount channelcount:(nsinteger) channelcount imageheight:(float) imageheight { cgsize imagesize = cgsizemake(samplecount, imageheight); uigraphicsbeginimagecontext(imagesize); cgcontextref context = uigraphicsgetcurrentcontext(); cgcontextsetfillcolorwithcolor(context, [uicolor blackcolor].cgcolor); cgcontextsetalpha(context,1.0); cgrect rect; rect.size = imagesize; rect.origin.x = 0; rect.origin.y = 0; cgcolorref leftcolor = [[uicolor whitecolor] cgcolor]; cgcolorref rightcolor = [[uicolor redcolor] cgcolor]; cgcontextfillrect(context, rect); cgcontextsetlinewidth(context, 1.0); float halfgraphheight = (imageheight / 2) / (float) channelcount ; float centerleft = halfgraphheight; float centerright = (halfgraphheight*3) ; float sampleadjustmentfactor = (imageheight/ (float) channelcount) / (float) normalizemax; (nsinteger intsample = 0 ; intsample < samplecount ; intsample ++ ) { sint16 left = *samples++; float pixels = (float) left; pixels *= sampleadjustmentfactor; cgcontextmovetopoint(context, intsample, centerleft-pixels); cgcontextaddlinetopoint(context, intsample, centerleft+pixels); cgcontextsetstrokecolorwithcolor(context, leftcolor); cgcontextstrokepath(context); if (channelcount==2) { sint16 right = *samples++; float pixels = (float) right; pixels *= sampleadjustmentfactor; cgcontextmovetopoint(context, intsample, centerright - pixels); cgcontextaddlinetopoint(context, intsample, centerright + pixels); cgcontextsetstrokecolorwithcolor(context, rightcolor); cgcontextstrokepath(context); } } // create new image uiimage *newimage = uigraphicsgetimagefromcurrentimagecontext(); // tidy uigraphicsendimagecontext(); return newimage; }
next, method takes avurlasset, , returns png image data
- (nsdata *) renderpngaudiopictogramforassett:(avurlasset *)songasset { nserror * error = nil; avassetreader * reader = [[avassetreader alloc] initwithasset:songasset error:&error]; avassettrack * songtrack = [songasset.tracks objectatindex:0]; nsdictionary* outputsettingsdict = [[nsdictionary alloc] initwithobjectsandkeys: [nsnumber numberwithint:kaudioformatlinearpcm],avformatidkey, // [nsnumber numberwithint:44100.0],avsampleratekey, /*not supported*/ // [nsnumber numberwithint: 2],avnumberofchannelskey, /*not supported*/ [nsnumber numberwithint:16],avlinearpcmbitdepthkey, [nsnumber numberwithbool:no],avlinearpcmisbigendiankey, [nsnumber numberwithbool:no],avlinearpcmisfloatkey, [nsnumber numberwithbool:no],avlinearpcmisnoninterleaved, nil]; avassetreadertrackoutput* output = [[avassetreadertrackoutput alloc] initwithtrack:songtrack outputsettings:outputsettingsdict]; [reader addoutput:output]; [output release]; uint32 samplerate,channelcount; nsarray* formatdesc = songtrack.formatdescriptions; for(unsigned int = 0; < [formatdesc count]; ++i) { cmaudioformatdescriptionref item = (cmaudioformatdescriptionref)[formatdesc objectatindex:i]; const audiostreambasicdescription* fmtdesc = cmaudioformatdescriptiongetstreambasicdescription (item); if(fmtdesc ) { samplerate = fmtdesc->msamplerate; channelcount = fmtdesc->mchannelsperframe; // nslog(@"channels:%u, bytes/packet: %u, samplerate %f",fmtdesc->mchannelsperframe, fmtdesc->mbytesperpacket,fmtdesc->msamplerate); } } uint32 bytespersample = 2 * channelcount; sint16 normalizemax = 0; nsmutabledata * fullsongdata = [[nsmutabledata alloc] init]; [reader startreading]; uint64 totalbytes = 0; sint64 totalleft = 0; sint64 totalright = 0; nsinteger sampletally = 0; nsinteger samplesperpixel = samplerate / 50; while (reader.status == avassetreaderstatusreading){ avassetreadertrackoutput * trackoutput = (avassetreadertrackoutput *)[reader.outputs objectatindex:0]; cmsamplebufferref samplebufferref = [trackoutput copynextsamplebuffer]; if (samplebufferref){ cmblockbufferref blockbufferref = cmsamplebuffergetdatabuffer(samplebufferref); size_t length = cmblockbuffergetdatalength(blockbufferref); totalbytes += length; nsautoreleasepool *wader = [[nsautoreleasepool alloc] init]; nsmutabledata * data = [nsmutabledata datawithlength:length]; cmblockbuffercopydatabytes(blockbufferref, 0, length, data.mutablebytes); sint16 * samples = (sint16 *) data.mutablebytes; int samplecount = length / bytespersample; (int = 0; < samplecount ; ++) { sint16 left = *samples++; totalleft += left; sint16 right; if (channelcount==2) { right = *samples++; totalright += right; } sampletally++; if (sampletally > samplesperpixel) { left = totalleft / sampletally; sint16 fix = abs(left); if (fix > normalizemax) { normalizemax = fix; } [fullsongdata appendbytes:&left length:sizeof(left)]; if (channelcount==2) { right = totalright / sampletally; sint16 fix = abs(right); if (fix > normalizemax) { normalizemax = fix; } [fullsongdata appendbytes:&right length:sizeof(right)]; } totalleft = 0; totalright = 0; sampletally = 0; } } [wader drain]; cmsamplebufferinvalidate(samplebufferref); cfrelease(samplebufferref); } } nsdata * finaldata = nil; if (reader.status == avassetreaderstatusfailed || reader.status == avassetreaderstatusunknown){ // went wrong. return nil return nil; } if (reader.status == avassetreaderstatuscompleted){ nslog(@"rendering output graphics using normalizemax %d",normalizemax); uiimage *test = [self audioimagegraph:(sint16 *) fullsongdata.bytes normalizemax:normalizemax samplecount:fullsongdata.length / 4 channelcount:2 imageheight:100]; finaldata = imagetodata(test); } [fullsongdata release]; [reader release]; return finaldata; }
logarithmic version of averaging , render methods
-(uiimage *) audioimageloggraph:(float32 *) samples normalizemax:(float32) normalizemax samplecount:(nsinteger) samplecount channelcount:(nsinteger) channelcount imageheight:(float) imageheight { cgsize imagesize = cgsizemake(samplecount, imageheight); uigraphicsbeginimagecontext(imagesize); cgcontextref context = uigraphicsgetcurrentcontext(); cgcontextsetfillcolorwithcolor(context, [uicolor blackcolor].cgcolor); cgcontextsetalpha(context,1.0); cgrect rect; rect.size = imagesize; rect.origin.x = 0; rect.origin.y = 0; cgcolorref leftcolor = [[uicolor whitecolor] cgcolor]; cgcolorref rightcolor = [[uicolor redcolor] cgcolor]; cgcontextfillrect(context, rect); cgcontextsetlinewidth(context, 1.0); float halfgraphheight = (imageheight / 2) / (float) channelcount ; float centerleft = halfgraphheight; float centerright = (halfgraphheight*3) ; float sampleadjustmentfactor = (imageheight/ (float) channelcount) / (normalizemax - noisefloor) / 2; (nsinteger intsample = 0 ; intsample < samplecount ; intsample ++ ) { float32 left = *samples++; float pixels = (left - noisefloor) * sampleadjustmentfactor; cgcontextmovetopoint(context, intsample, centerleft-pixels); cgcontextaddlinetopoint(context, intsample, centerleft+pixels); cgcontextsetstrokecolorwithcolor(context, leftcolor); cgcontextstrokepath(context); if (channelcount==2) { float32 right = *samples++; float pixels = (right - noisefloor) * sampleadjustmentfactor; cgcontextmovetopoint(context, intsample, centerright - pixels); cgcontextaddlinetopoint(context, intsample, centerright + pixels); cgcontextsetstrokecolorwithcolor(context, rightcolor); cgcontextstrokepath(context); } } // create new image uiimage *newimage = uigraphicsgetimagefromcurrentimagecontext(); // tidy uigraphicsendimagecontext(); return newimage; }
- (nsdata *) renderpngaudiopictogramlogforassett:(avurlasset *)songasset { nserror * error = nil; avassetreader * reader = [[avassetreader alloc] initwithasset:songasset error:&error]; avassettrack * songtrack = [songasset.tracks objectatindex:0]; nsdictionary* outputsettingsdict = [[nsdictionary alloc] initwithobjectsandkeys: [nsnumber numberwithint:kaudioformatlinearpcm],avformatidkey, // [nsnumber numberwithint:44100.0],avsampleratekey, /*not supported*/ // [nsnumber numberwithint: 2],avnumberofchannelskey, /*not supported*/ [nsnumber numberwithint:16],avlinearpcmbitdepthkey, [nsnumber numberwithbool:no],avlinearpcmisbigendiankey, [nsnumber numberwithbool:no],avlinearpcmisfloatkey, [nsnumber numberwithbool:no],avlinearpcmisnoninterleaved, nil]; avassetreadertrackoutput* output = [[avassetreadertrackoutput alloc] initwithtrack:songtrack outputsettings:outputsettingsdict]; [reader addoutput:output]; [output release]; uint32 samplerate,channelcount; nsarray* formatdesc = songtrack.formatdescriptions; for(unsigned int = 0; < [formatdesc count]; ++i) { cmaudioformatdescriptionref item = (cmaudioformatdescriptionref)[formatdesc objectatindex:i]; const audiostreambasicdescription* fmtdesc = cmaudioformatdescriptiongetstreambasicdescription (item); if(fmtdesc ) { samplerate = fmtdesc->msamplerate; channelcount = fmtdesc->mchannelsperframe; // nslog(@"channels:%u, bytes/packet: %u, samplerate %f",fmtdesc->mchannelsperframe, fmtdesc->mbytesperpacket,fmtdesc->msamplerate); } } uint32 bytespersample = 2 * channelcount; float32 normalizemax = noisefloor; nslog(@"normalizemax = %f",normalizemax); nsmutabledata * fullsongdata = [[nsmutabledata alloc] init]; [reader startreading]; uint64 totalbytes = 0; float64 totalleft = 0; float64 totalright = 0; float32 sampletally = 0; nsinteger samplesperpixel = samplerate / 50; while (reader.status == avassetreaderstatusreading){ avassetreadertrackoutput * trackoutput = (avassetreadertrackoutput *)[reader.outputs objectatindex:0]; cmsamplebufferref samplebufferref = [trackoutput copynextsamplebuffer]; if (samplebufferref){ cmblockbufferref blockbufferref = cmsamplebuffergetdatabuffer(samplebufferref); size_t length = cmblockbuffergetdatalength(blockbufferref); totalbytes += length; nsautoreleasepool *wader = [[nsautoreleasepool alloc] init]; nsmutabledata * data = [nsmutabledata datawithlength:length]; cmblockbuffercopydatabytes(blockbufferref, 0, length, data.mutablebytes); sint16 * samples = (sint16 *) data.mutablebytes; int samplecount = length / bytespersample; (int = 0; < samplecount ; ++) { float32 left = (float32) *samples++; left = decibel(left); left = minmaxx(left,noisefloor,0); totalleft += left; float32 right; if (channelcount==2) { right = (float32) *samples++; right = decibel(right); right = minmaxx(right,noisefloor,0); totalright += right; } sampletally++; if (sampletally > samplesperpixel) { left = totalleft / sampletally; if (left > normalizemax) { normalizemax = left; } // nslog(@"left average = %f, normalizemax = %f",left,normalizemax); [fullsongdata appendbytes:&left length:sizeof(left)]; if (channelcount==2) { right = totalright / sampletally; if (right > normalizemax) { normalizemax = right; } [fullsongdata appendbytes:&right length:sizeof(right)]; } totalleft = 0; totalright = 0; sampletally = 0; } } [wader drain]; cmsamplebufferinvalidate(samplebufferref); cfrelease(samplebufferref); } } nsdata * finaldata = nil; if (reader.status == avassetreaderstatusfailed || reader.status == avassetreaderstatusunknown){ // went wrong. handle it. } if (reader.status == avassetreaderstatuscompleted){ // you're done. worked. nslog(@"rendering output graphics using normalizemax %f",normalizemax); uiimage *test = [self audioimageloggraph:(float32 *) fullsongdata.bytes normalizemax:normalizemax samplecount:fullsongdata.length / (sizeof(float32) * 2) channelcount:2 imageheight:100]; finaldata = imagetodata(test); } [fullsongdata release]; [reader release]; return finaldata; }
**now init method "the business"** - (id) initwithmpmediaitem:(mpmediaitem*) item completionblock:(void (^)(uiimage* delayedimagepreparation))completionblock { nsfilemanager *fman = [nsfilemanager defaultmanager]; nsstring *assetpictogramfilepath = [[self class] cachedaudiopictogrampathformpmediaitem:item]; if ([fman fileexistsatpath:assetpictogramfilepath]) { nslog(@"returning cached waveform pictogram: %@",[assetpictogramfilepath lastpathcomponent]); self = [self initwithcontentsoffile:assetpictogramfilepath]; return self; } nsstring *assetfilepath = [[self class] cachedaudiofilepathformpmediaitem:item]; nsurl *assetfileurl = [nsurl fileurlwithpath:assetfilepath]; if ([fman fileexistsatpath:assetfilepath]) { nslog(@"scanning cached audio data create uiimage file: %@",[assetfilepath lastpathcomponent]); [assetfileurl retain]; [assetpictogramfilepath retain]; [nsthread mcsm_performblockinbackground: ^{ avurlasset *asset = [[avurlasset alloc] initwithurl:assetfileurl options:nil]; nsdata *waveformdata = [self renderpngaudiopictogramforassett:asset]; [waveformdata writetofile:assetpictogramfilepath atomically:yes]; [assetfileurl release]; [assetpictogramfilepath release]; if (completionblock) { [waveformdata retain]; [nsthread mcsm_performblockonmainthread:^{ uiimage *result = [uiimage imagewithdata:waveformdata]; nslog(@"returning rendered pictogram on main thread (%d bytes %@ data in uiimage %0.0f x %0.0f pixels)",waveformdata.length, [imgextuppercasestring],result.size.width,result.size.height); completionblock(result); [waveformdata release]; }]; } }]; return nil; } else { nsstring *assetfolder = [[self class] assetcachefolder]; [fman createdirectoryatpath:assetfolder withintermediatedirectories:yes attributes:nil error:nil]; nslog(@"preparing import audio asset data %@",[assetfilepath lastpathcomponent]); [assetpictogramfilepath retain]; [assetfileurl retain]; tslibraryimport* import = [[tslibraryimport alloc] init]; nsurl * asseturl = [item valueforproperty:mpmediaitempropertyasseturl]; [import importasset:asseturl tourl:assetfileurl completionblock:^(tslibraryimport* import) { //check status , error properties of //tslibraryimport if (import.error) { nslog (@"audio data import failed:%@",import.error); } else{ nslog (@"creating waveform pictogram file: %@", [assetpictogramfilepath lastpathcomponent]); avurlasset *asset = [[avurlasset alloc] initwithurl:assetfileurl options:nil]; nsdata *waveformdata = [self renderpngaudiopictogramforassett:asset]; [waveformdata writetofile:assetpictogramfilepath atomically:yes]; if (completionblock) { [waveformdata retain]; [nsthread mcsm_performblockonmainthread:^ { uiimage *result = [uiimage imagewithdata:waveformdata]; nslog(@"returning rendered pictogram on main thread (%d bytes %@ data in uiimage %0.0f x %0.0f pixels)",waveformdata.length,[imgext uppercasestring],result.size.width,result.size.height); completionblock(result); [waveformdata release]; }]; } } [assetpictogramfilepath release]; [assetfileurl release]; } ]; return nil; } }
an example of invoking :
-(void) importmediaitem {
mpmediaitem* item = [self mediaitem]; // since needing playback, save url cached audio. [url release]; url = [[uiimage cachedaudiourlformpmediaitem:item] retain]; [waveformimage release]; waveformimage = [[uiimage alloc ] initwithmpmediaitem:item completionblock:^(uiimage* delayedimagepreparation){ waveformimage = [delayedimagepreparation retain]; [self displaywaveformimage]; }]; if (waveformimage) { [waveformimage retain]; [self displaywaveformimage]; } }
i have added class methods,librabries,nsthread classes project,everything got fixed,but not geting method call,.its messy
create view controller , add importmediaitem method.
ensure media item not nil. can current track ipad player follows:
mpmusicplayercontroller* player = [mpmusicplayercontroller ipodmusicplayer]; mpmediaitem *item = [player nowplayingitem]; in viewdidappear method, call importmediaitem.
add displaywaveformimage method call back, , create uiimageview image returned.
be sure start ipod player before run app.
then works.
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