Objective-C/AVFoundationExporter/AVFoundationExporter.m

/*
    Copyright (C) 2016 Apple Inc. All Rights Reserved.
    See LICENSE.txt for this sample’s licensing information
    
    Abstract:
    This file shows an example of using the export and metadata functions in AVFoundation as a part of a command line tool for simple exports.
*/
 
@import Foundation;
@import AVFoundation;
 
// ---------------------------------------------------------------------------
//      Convenience Functions
// ---------------------------------------------------------------------------
 
static void printNSString(NSString *string);
static void printArgs(int argc, const char **argv);
 
 
// ---------------------------------------------------------------------------
//      AAPLExporter Class Interface
// ---------------------------------------------------------------------------
@interface AAPLExporter: NSObject {
    NSString *programName;
    NSString *exportType;
    NSString *preset;
    NSString *sourcePath;
    NSString *destinationPath;
    NSString *fileType;
    NSNumber *progress;
    NSNumber *startSeconds;
    NSNumber *durationSeconds;
    BOOL showProgress;
    BOOL verbose;
    BOOL exportFailed;
    BOOL exportComplete;
    BOOL listTracks;
    BOOL listMetadata;
    BOOL removePreExistingFiles;
}
 
@property (copy) NSString *programName;
@property (copy) NSString *exportType;
@property (copy) NSString *preset;
@property (copy) NSString *sourcePath;
@property (copy) NSString *destinationPath;
@property (copy) NSString *fileType;
@property (strong) NSNumber *progress;
@property (strong) NSNumber *startSeconds;
@property (strong) NSNumber *durationSeconds;
@property (getter=isVerbose) BOOL verbose;
@property BOOL showProgress;
@property BOOL exportFailed;
@property BOOL exportComplete;
@property BOOL listTracks;
@property BOOL listMetadata;
@property BOOL removePreExistingFiles;
 
- (id)initWithArgs:(int)argc argv:(const char **)argv environ:(const char **)environ;
- (void)printUsage;
 
- (int)run;
 
- (NSArray *)addNewMetadata:(NSArray *)sourceMetadataList presetName:(NSString *)presetName;
 
+ (void)doListPresets;
- (void)doListTracks:(NSString *)assetPath;
- (void)doListMetadata:(NSString *)assetPath;
 
 
@end
 
 
// ---------------------------------------------------------------------------
//      AAPLExporter Class Implementation
// ---------------------------------------------------------------------------
 
@implementation AAPLExporter
 
@synthesize programName, exportType, preset;
@synthesize sourcePath, destinationPath, progress, fileType;
@synthesize startSeconds, durationSeconds;
@synthesize verbose, showProgress, exportComplete, exportFailed; 
@synthesize listTracks, listMetadata;
@synthesize removePreExistingFiles;
 
-(id) initWithArgs: (int) argc  argv: (const char **) argv environ: (const char **) environ
{
    self = [super init];
 
    if (self == nil) {
        return nil;
    }
 
    printArgs(argc,argv);
    
    BOOL gotpreset = NO;
    BOOL gotsource = NO;
    BOOL gotout = NO;
    BOOL parseOK = NO;
    BOOL listPresets = NO;
    [self setProgramName:[NSString stringWithUTF8String: *argv++]];
    argc--;
    while ( argc > 0 && **argv == '-' )
    {
        const char* args = &(*argv)[1];
        
        argc--;
        argv++;
        
        if ( ! strcmp ( args, "source" ) )
        {
            [self setSourcePath: [NSString stringWithUTF8String: *argv++] ];
            gotsource = YES;
            argc--;
        }
        else if (( ! strcmp ( args, "dest" )) || ( ! strcmp ( args, "destination" )) )
        {
            [self setDestinationPath: [NSString stringWithUTF8String: *argv++]];
            gotout = YES;
            argc--;
        }
        else if ( ! strcmp ( args, "preset" ) )
        {
            [self setPreset: [NSString stringWithUTF8String: *argv++]];
            gotpreset = YES;
            argc--;
        }
        else if ( ! strcmp ( args, "replace" ) )
        {
            [self setRemovePreExistingFiles: YES];
        }
        else if ( ! strcmp ( args, "filetype" ) )
        {
            [self setFileType: [NSString stringWithUTF8String: *argv++]];
            argc--;
        }
        else if ( ! strcmp ( args, "verbose" ) )
        {
            [self setVerbose:YES];
        }
        else if ( ! strcmp ( args, "progress" ) )
        {
            [self setShowProgress: YES];
        }
        else if ( ! strcmp ( args, "start" ) )
        {
            [self setStartSeconds: [NSNumber numberWithFloat:[[NSString stringWithUTF8String: *argv++] floatValue]]];
            argc--;
        }
        else if ( ! strcmp ( args, "duration" ) )
        {
            [self setDurationSeconds: [NSNumber numberWithFloat:[[NSString stringWithUTF8String: *argv++] floatValue]]];
            argc--;
        }
        else if ( ! strcmp ( args, "listpresets" ) )
        {
            listPresets = YES;
            parseOK = YES;
        }
        else if ( ! strcmp ( args, "listtracks" ) )
        {
            [self setListTracks: YES];
            parseOK = YES;
        }
        else if ( ! strcmp ( args, "listmetadata" ) )
        {
            [self setListMetadata: YES];
            parseOK = YES;
        }
        else if ( ! strcmp ( args, "help" ) )
        {
            [self printUsage];
        }
        else {
            printf("Invalid input parameter: %s\n", args );
            [self printUsage];
            return nil;
        }
    }
    [self setProgress: [NSNumber numberWithFloat:(float)0.0]];
    [self setExportFailed: NO];
    [self setExportComplete: NO];
    
    if (listPresets) {
        [AAPLExporter doListPresets];
    }
    
    if ([self isVerbose]) {
        printNSString([NSString stringWithFormat:@"Running: %@\n", [self programName]]);
    }
    
    // There must be a source and either a preset and output (the normal case) or parseOK set for a listing
    if ((gotsource == NO)  || ((parseOK == NO) && ((gotpreset == NO) || (gotout == NO)))) {
        [self printUsage];
        return nil;
    }
    return self;
}
 
 
-(void) printUsage
{
    printf("AVFoundationExporter - usage:\n");
    printf("    ./AVFoundationExporter [-parameter <value> ...]\n");
    printf("     parameters are all preceded by a -<parameterName>.  The order of the parameters is unimportant.\n");
    printf("     Required parameters are  -preset <presetName> -source <sourceFileURL> -dest <outputFileURL>\n");
    printf("     Source and destination URL strings cannot contain spaces.\n");
    printf("     Available parameters are:\n");
    printf("        -preset <preset name>.  The preset name eg: AVAssetExportPreset640x480 AVAssetExportPresetAppleM4VWiFi. Use -listpresets to see a full list.\n");
    printf("        -destination (or -dest) <outputFileURL>\n");
    printf("        -source <sourceMovieURL>\n");
    printf("        -replace   If there is a preexisting file at the destination location, remove it before exporting.");
    printf("        -filetype <file type string> The file type (eg com.apple.m4v-video) for the output file.  If not specified, the first supported type will be used.\n");
    printf("        -start <start time>  time in seconds (decimal are OK).  Removes the startClip time from the beginning of the movie before exporting.\n");
    printf("        -duration <duration>  time in seconds (decimal are OK).  Trims the movie to this duration before exporting.  \n");
    printf("    Also available are some setup options:\n");
    printf("        -verbose  Print more information about the execution.\n");
    printf("        -progress  Show progress information.\n");
    printf("        -listpresets  For sourceMovieURL sources only, lists the tracks in the source movie before the export.  \n");
    printf("        -listtracks  For sourceMovieURL sources only, lists the tracks in the source movie before the export.  \n");
    printf("            Always lists the tracks in the destination asset at the end of the export.\n");
    printf("        -listmetadata  Lists the metadata in the source movie before the export.  \n");
    printf("            Also lists the metadata in the destination asset at the end of the export.\n");
    printf("    Sample export lines:\n");
    printf("    ./AVFoundationExporter -dest /tmp/testOut.m4v -replace -preset AVAssetExportPresetAppleM4ViPod -listmetadata -source /path/to/myTestMovie.m4v\n");
    printf("    ./AVFoundationExporter -destination /tmp/testOut.mov -preset AVAssetExportPreset640x480 -listmetadata -listtracks -source /path/to/myTestMovie.mov\n");
}
 
 
static dispatch_time_t getDispatchTimeFromSeconds(float seconds) {
    long long milliseconds = seconds * 1000.0;
    dispatch_time_t waitTime = dispatch_time( DISPATCH_TIME_NOW, 1000000LL * milliseconds );
    return waitTime;
}
 
- (int)run
{   
    NSURL   *sourceURL = nil;
    AVAssetExportSession *avsession = nil;
    NSURL   *destinationURL = nil;
    BOOL    success = YES;
 
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    NSParameterAssert( [self sourcePath] != nil );
 
    if ([self listTracks] && [self sourcePath]) {
        [self doListTracks:[self sourcePath]];
    }
    if ([self listMetadata] && [self sourcePath]) {
        [self doListMetadata:[self sourcePath]];
    }
    if ([self destinationPath] == nil) {
        NSLog(@"No output path specified, only listing tracks and/or metadata, export was not performed.");
        goto bail;
    }
    if ([self preset] == nil) {
        NSLog(@"No preset specified, only listing tracks and/or metadata, export was not performed.");
        goto bail;
    }
    
    if ( [self isVerbose] && [self sourcePath] ) {
        printNSString([NSString stringWithFormat:@"all av asset presets:%@", [AVAssetExportSession allExportPresets]]);
    }
    
    if ([self sourcePath] != nil) {
        sourceURL = [[NSURL fileURLWithPath: [self sourcePath] isDirectory: NO] retain];
    }
 
    AVAsset *sourceAsset = nil;
    NSError* error = nil;
    
    if ([self isVerbose]) {
        printNSString([NSString stringWithFormat:@"AVAssetExport for preset:%@ to with source:%@", [self preset], [destinationURL path]]);
    }
    
    destinationURL = [NSURL fileURLWithPath: [self destinationPath] isDirectory: NO];
    if ([self removePreExistingFiles] && [[NSFileManager defaultManager] fileExistsAtPath:[self destinationPath]]) {
        if ([self isVerbose]) {
            printNSString([NSString stringWithFormat:@"Removing re-existing destination file at:%@", destinationURL]);
        }
        [[NSFileManager defaultManager] removeItemAtURL:destinationURL error:&error];
    }
 
    sourceAsset = [[[AVURLAsset alloc] initWithURL:sourceURL options:nil] autorelease];
 
    if ([self isVerbose]) {
        printNSString([NSString stringWithFormat:@"Compatible av asset presets:%@", [AVAssetExportSession exportPresetsCompatibleWithAsset:sourceAsset]]);
    }
    avsession = [[AVAssetExportSession alloc] initWithAsset:sourceAsset presetName:[self preset]];
 
    [avsession setOutputURL:destinationURL];
 
    if ([self fileType] != nil) {
        [avsession setOutputFileType:[self fileType]];
    }
    else {
        [avsession setOutputFileType:[[avsession supportedFileTypes] objectAtIndex:0]];
    }
    
    if ([self isVerbose]) {
        printNSString([NSString stringWithFormat:@"Created AVAssetExportSession: %p", avsession]);
        printNSString([NSString stringWithFormat:@"presetName:%@", [avsession presetName]]);
        printNSString([NSString stringWithFormat:@"source URL:%@", [sourceURL path]]);
        printNSString([NSString stringWithFormat:@"destination URL:%@", [[avsession outputURL] path]]);
        printNSString([NSString stringWithFormat:@"output file type:%@", [avsession outputFileType]]);
    }
    
    // Add a metadata item to indicate how thie destination file was created.
    NSArray *sourceMetadataList = [avsession metadata];
    sourceMetadataList = [self addNewMetadata: sourceMetadataList presetName:[self preset]];
    [avsession setMetadata:sourceMetadataList];
    
    // Set up the time range
    CMTime startTime = kCMTimeZero;
    CMTime durationTime = kCMTimePositiveInfinity;
    
    if ([self startSeconds] != nil) {
        startTime = CMTimeMake([[self startSeconds] floatValue] * 1000, 1000);
    }
    if ([self durationSeconds] != nil) {
        durationTime = CMTimeMake([[self durationSeconds] floatValue] * 1000, 1000);
    }
    CMTimeRange exportTimeRange = CMTimeRangeMake(startTime, durationTime);
    [avsession setTimeRange:exportTimeRange];
    
    // start a fresh pool for the export.
    [pool drain];
    pool = [[NSAutoreleasePool alloc] init];
    
    //  Set up a semaphore for the completion handler and progress timer
    dispatch_semaphore_t sessionWaitSemaphore = dispatch_semaphore_create( 0 );
    
    void (^completionHandler)(void) = ^(void)
    {
        dispatch_semaphore_signal(sessionWaitSemaphore);
    };
    
    // do it.
    [avsession exportAsynchronouslyWithCompletionHandler:completionHandler];
 
    do {
        dispatch_time_t dispatchTime = DISPATCH_TIME_FOREVER;  // if we dont want progress, we will wait until it finishes.
        if ([self showProgress]) {
            dispatchTime = getDispatchTimeFromSeconds((float)1.0);
            printNSString([NSString stringWithFormat:@"AVAssetExport running  progress=%3.2f%%", [avsession progress]*100]);
        }
        dispatch_semaphore_wait(sessionWaitSemaphore, dispatchTime);
    } while( [avsession status] < AVAssetExportSessionStatusCompleted );
 
    if ([self showProgress]) {
        printNSString([NSString stringWithFormat:@"AVAssetExport finished progress=%3.2f", [avsession progress]*100]);
    }
    
    [avsession release];
    avsession = nil;
    
    if ([self listMetadata] && [self destinationPath]) {
        [self doListMetadata:[self destinationPath]];
    }
    if ([self listTracks] && [self destinationPath]) {
        [self doListTracks:[self destinationPath]];
    }
    
    printNSString([NSString stringWithFormat:@"Finished export of %@ to %@ using preset:%@ success=%s\n", [self sourcePath], [self destinationPath], [self preset], (success ? "YES" : "NO")]);
    
bail:
    [sourceURL release];
    
    [pool drain];
    
    return success;
}
 
 
- (NSArray *) addNewMetadata: (NSArray *)sourceMetadataList presetName:(NSString *)presetName
{
    // This method creates a few new metadata items in different keySpaces to be inserted into the exported file along with the metadata that
    // was in the original source.  
    // Depending on the output file format, not all of these items will be valid and not all of them will come through to the destination.
    
    AVMutableMetadataItem *newUserDataCommentItem = [[[AVMutableMetadataItem alloc] init] autorelease];
    [newUserDataCommentItem setKeySpace:AVMetadataKeySpaceQuickTimeUserData];
    [newUserDataCommentItem setKey:AVMetadataQuickTimeUserDataKeyComment];
    [newUserDataCommentItem setValue:[NSString stringWithFormat:@"QuickTime userdata: Exported to preset %@ using AVFoundationExporter at: %@", presetName,
                                      [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle: NSDateFormatterShortStyle]]];
    
    AVMutableMetadataItem *newMetaDataCommentItem = [[[AVMutableMetadataItem alloc] init] autorelease];
    [newMetaDataCommentItem setKeySpace:AVMetadataKeySpaceQuickTimeMetadata];
    [newMetaDataCommentItem setKey:AVMetadataQuickTimeMetadataKeyComment];
    [newMetaDataCommentItem setValue:[NSString stringWithFormat:@"QuickTime metadata: Exported to preset %@ using AVFoundationExporter at: %@", presetName,
                                      [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle: NSDateFormatterShortStyle]]];
    
    AVMutableMetadataItem *newiTunesCommentItem = [[[AVMutableMetadataItem alloc] init] autorelease];
    [newiTunesCommentItem setKeySpace:AVMetadataKeySpaceiTunes];
    [newiTunesCommentItem setKey:AVMetadataiTunesMetadataKeyUserComment];
    [newiTunesCommentItem setValue:[NSString stringWithFormat:@"iTunes metadata: Exported to preset %@ using AVFoundationExporter at: %@", presetName, 
                                    [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterMediumStyle timeStyle: NSDateFormatterShortStyle]]];
    
    NSArray *newMetadata = [NSArray arrayWithObjects:newUserDataCommentItem, newMetaDataCommentItem, newiTunesCommentItem, nil];
    NSArray *newMetadataList = (sourceMetadataList == nil ? newMetadata : [sourceMetadataList arrayByAddingObjectsFromArray:newMetadata]);
    return newMetadataList;
}
 
 
+ (void) doListPresets
{ 
    //  A simple listing of the presets available for export
    printNSString(@"");
    printNSString(@"Presets available for AVFoundation export:");
    printNSString(@"  QuickTime movie presets:");
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPreset640x480]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPreset960x540]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPreset1280x720]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPreset1920x1080]);
    printNSString(@"  Audio only preset:");
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4A]);
    printNSString(@"  Apple device presets:");
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4VCellular]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4ViPod]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4V480pSD]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4VAppleTV]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4VWiFi]);
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleM4V720pHD]);
    printNSString(@"  Interim format (QuickTime movie) preset:");
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetAppleProRes422LPCM]);
    printNSString(@"  Passthrough preset:");
    printNSString([NSString stringWithFormat:@"    %@", AVAssetExportPresetPassthrough]);
    printNSString(@"");
}
 
 
- (void)doListTracks:(NSString *)assetPath
{ 
    //  A simple listing of the tracks in the asset provided
    NSURL *sourceURL = [NSURL fileURLWithPath: assetPath isDirectory: NO];
    if (sourceURL) {
        AVURLAsset *sourceAsset = [[[AVURLAsset alloc] initWithURL:sourceURL options:nil] autorelease];
        printNSString([NSString stringWithFormat:@"Listing tracks for asset from url:%@", [sourceURL path]]);
        NSInteger index = 0;
        for (AVAssetTrack *track in [sourceAsset tracks]) {
            [track retain];
            printNSString([ NSString stringWithFormat:@"  Track index:%ld, trackID:%d, mediaType:%@, enabled:%d, isSelfContained:%d", index, [track trackID], [track mediaType], [track isEnabled], [track isSelfContained] ] );
            index++;
            [track release];
        }
    }
}
 
enum {
    kMaxMetadataValueLength = 80,
};
 
- (void)doListMetadata:(NSString *)assetPath
{
    //  A simple listing of the metadata in the asset provided
    NSURL *sourceURL = [NSURL fileURLWithPath: assetPath isDirectory: NO];
    if (sourceURL) {
        AVURLAsset *sourceAsset = [[[AVURLAsset alloc] initWithURL:sourceURL options:nil] autorelease];
        NSLog(@"Listing metadata for asset from url:%@", [sourceURL path]);
        for (NSString *format in [sourceAsset availableMetadataFormats]) {
            NSLog(@"Metadata for format:%@", format);
            for (AVMetadataItem *item in [sourceAsset metadataForFormat:format]) {
                NSObject *key = [item key];
                NSString *itemValue = [[item value] description];
                if ([itemValue length] > kMaxMetadataValueLength) {
                    itemValue = [NSString stringWithFormat:@"%@ ...", [itemValue substringToIndex:kMaxMetadataValueLength-4]];
                }
                if ([key isKindOfClass: [NSNumber class]]) {
                    NSInteger longValue = [(NSNumber *)key longValue];
                    char *charSource = (char *)&longValue;
                    char charValue[5] = {0};
                    charValue[0] = charSource[3];
                    charValue[1] = charSource[2];
                    charValue[2] = charSource[1];
                    charValue[3] = charSource[0];
                    NSString *stringKey = [[[NSString alloc] initWithBytes: charValue length:4 encoding:NSMacOSRomanStringEncoding] autorelease];
                    printNSString([NSString stringWithFormat:@"  metadata item key:%@ (%ld), keySpace:%@ commonKey:%@ value:%@", stringKey, longValue, [item keySpace], [item commonKey], itemValue]);
                }
                else {
                    printNSString([NSString stringWithFormat:@"  metadata item key:%@, keySpace:%@ commonKey:%@ value:%@", [item key], [item keySpace], [item commonKey], itemValue]);
                }
            }
        }
    }
}
 
 
@end
 
 
// ---------------------------------------------------------------------------
//      main
// ---------------------------------------------------------------------------
 
 
int main (int argc, const char * argv[], const char* environ[])
{
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
    
    AAPLExporter* exportObj = [[AAPLExporter alloc] initWithArgs:argc argv:argv  environ:environ];
    BOOL success;
    if (exportObj)
        success = [exportObj run];
    else {
        success = NO;
    }
    
    [exportObj release];
    [pool release];
    
    return ((success == YES) ? 0 : -1);
}
 
 
// ---------------------------------------------------------------------------
//      printNSString
// ---------------------------------------------------------------------------
static void printNSString(NSString *string)
{
    printf("%s\n", [string cStringUsingEncoding:NSUTF8StringEncoding]);
}
 
// ---------------------------------------------------------------------------
//      printArgs
// ---------------------------------------------------------------------------
static void printArgs(int argc, const char **argv)
{
    int i;
    for( i = 0; i < argc; i++ )
        printf("%s ", argv[i]);
    printf("\n");
}


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