[FFmpeg] Support files with chapters

Support file chapters, including metadata reading for each chapter.

Signed-off-by: Christopher Snowhill <kode54@gmail.com>

Plugins/FFMPEG/FFMPEG.xcodeproj/project.pbxproj

@@ -23,6 +23,7 @@
 		83AA7D0E279EBCC600087AA4 /* libswresample.4.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = 83AA7D0A279EBCC600087AA4 /* libswresample.4.dylib */; };
 		83AA7D0F279EBCC600087AA4 /* libavformat.59.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = 83AA7D0B279EBCC600087AA4 /* libavformat.59.dylib */; };
 		83B72E3927904557006007A3 /* libfdk-aac.2.dylib in Frameworks */ = {isa = PBXBuildFile; fileRef = 83B72E3827904557006007A3 /* libfdk-aac.2.dylib */; };
+		83CBC5AA2866F75B00F2753B /* FFMPEGContainer.m in Sources */ = {isa = PBXBuildFile; fileRef = 83CBC5A92866F75B00F2753B /* FFMPEGContainer.m */; };
 		83E22FC62772FD32000015EE /* libbz2.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 83E22FC52772FD32000015EE /* libbz2.tbd */; };
 		83E22FC82772FD3A000015EE /* AudioToolbox.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 83E22FC72772FD3A000015EE /* AudioToolbox.framework */; };
 		8D5B49B4048680CD000E48DA /* Cocoa.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 1058C7ADFEA557BF11CA2CBB /* Cocoa.framework */; };
@@ -65,6 +66,8 @@
 		83AA7D0A279EBCC600087AA4 /* libswresample.4.dylib */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = libswresample.4.dylib; path = ../../ThirdParty/ffmpeg/lib/libswresample.4.dylib; sourceTree = "<group>"; };
 		83AA7D0B279EBCC600087AA4 /* libavformat.59.dylib */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = libavformat.59.dylib; path = ../../ThirdParty/ffmpeg/lib/libavformat.59.dylib; sourceTree = "<group>"; };
 		83B72E3827904557006007A3 /* libfdk-aac.2.dylib */ = {isa = PBXFileReference; lastKnownFileType = "compiled.mach-o.dylib"; name = "libfdk-aac.2.dylib"; path = "../../ThirdParty/fdk-aac/lib/libfdk-aac.2.dylib"; sourceTree = "<group>"; };
+		83CBC5A82866F75B00F2753B /* FFMPEGContainer.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = FFMPEGContainer.h; sourceTree = "<group>"; };
+		83CBC5A92866F75B00F2753B /* FFMPEGContainer.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = FFMPEGContainer.m; sourceTree = "<group>"; };
 		83E22FC52772FD32000015EE /* libbz2.tbd */ = {isa = PBXFileReference; lastKnownFileType = "sourcecode.text-based-dylib-definition"; name = libbz2.tbd; path = usr/lib/libbz2.tbd; sourceTree = SDKROOT; };
 		83E22FC72772FD3A000015EE /* AudioToolbox.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = AudioToolbox.framework; path = System/Library/Frameworks/AudioToolbox.framework; sourceTree = SDKROOT; };
 		8D5B49B6048680CD000E48DA /* FFMPEG.bundle */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = FFMPEG.bundle; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -151,6 +154,8 @@
 				B09E94370D747FAD0064F138 /* Plugin.h */,
 				B09E942D0D747F410064F138 /* FFMPEGDecoder.h */,
 				B09E942E0D747F410064F138 /* FFMPEGDecoder.m */,
+				83CBC5A82866F75B00F2753B /* FFMPEGContainer.h */,
+				83CBC5A92866F75B00F2753B /* FFMPEGContainer.m */,
 			);
 			name = Classes;
 			sourceTree = "<group>";
@@ -276,6 +281,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				B09E942F0D747F410064F138 /* FFMPEGDecoder.m in Sources */,
+				83CBC5AA2866F75B00F2753B /* FFMPEGContainer.m in Sources */,
 				8356BCE927B37C6F0074E50C /* NSDictionary+Merge.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

Plugins/FFMPEG/FFMPEGContainer.h

@@ -0,0 +1,18 @@
+//
+//  FFMPEGContainer.h
+//  FFMPEG Plugin
+//
+//  Created by Christopher Snowhill on 6/25/22.
+//
+
+#import <Cocoa/Cocoa.h>
+
+#import "Plugin.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FFMPEGContainer : NSObject <CogContainer>
+
+@end
+
+NS_ASSUME_NONNULL_END

Plugins/FFMPEG/FFMPEGContainer.m

@@ -0,0 +1,199 @@
+//
+//  FFMPEGContainer.m
+//  FFMPEG Plugin
+//
+//  Created by Christopher Snowhill on 6/25/22.
+//
+
+#import "FFMPEGContainer.h"
+
+#import "FFMPEGDecoder.h"
+
+#import "Logging.h"
+
+@implementation FFMPEGContainer
+
++ (NSArray *)fileTypes {
+	return [FFMPEGDecoder fileTypes];
+}
+
++ (NSArray *)mimeTypes {
+	return [FFMPEGDecoder fileTypes];
+}
+
++ (float)priority {
+	return [FFMPEGDecoder priority];
+}
+
++ (NSArray *)urlsForContainerURL:(NSURL *)url {
+	if([url fragment]) {
+		// input url already has fragment defined - no need to expand further
+		return [NSMutableArray arrayWithObject:url];
+	}
+
+	id audioSourceClass = NSClassFromString(@"AudioSource");
+	id<CogSource> source = [audioSourceClass audioSourceForURL:url];
+
+	if(![source open:url])
+		return [NSArray array];
+
+	int errcode, i;
+	AVStream *stream;
+
+	AVFormatContext *formatCtx = NULL;
+	AVIOContext *ioCtx = NULL;
+
+	BOOL isStream = NO;
+
+	uint8_t *buffer = NULL;
+
+	// register all available codecs
+
+	if(([[url scheme] isEqualToString:@"http"] ||
+	    [[url scheme] isEqualToString:@"https"]) &&
+	   [[url pathExtension] isEqualToString:@"m3u8"]) {
+		[source close];
+		source = nil;
+
+		isStream = YES;
+
+		formatCtx = avformat_alloc_context();
+		if(!formatCtx) {
+			ALog(@"Unable to allocate AVFormat context");
+			return [NSArray array];
+		}
+
+		NSString *urlString = [url absoluteString];
+		if((errcode = avformat_open_input(&formatCtx, [urlString UTF8String], NULL, NULL)) < 0) {
+			char errDescr[4096];
+			av_strerror(errcode, errDescr, 4096);
+			ALog(@"Error opening file, errcode = %d, error = %s", errcode, errDescr);
+			return [NSArray array];
+		}
+	} else {
+		buffer = av_malloc(32 * 1024);
+		if(!buffer) {
+			ALog(@"Out of memory!");
+			[source close];
+			source = nil;
+			return [NSArray array];
+		}
+
+		ioCtx = avio_alloc_context(buffer, 32 * 1024, 0, (__bridge void *)source, ffmpeg_read, ffmpeg_write, ffmpeg_seek);
+		if(!ioCtx) {
+			ALog(@"Unable to create AVIO context");
+			av_free(buffer);
+			[source close];
+			source = nil;
+			return [NSArray array];
+		}
+
+		formatCtx = avformat_alloc_context();
+		if(!formatCtx) {
+			ALog(@"Unable to allocate AVFormat context");
+			buffer = ioCtx->buffer;
+			av_free(ioCtx);
+			av_free(buffer);
+			[source close];
+			source = nil;
+			return [NSArray array];
+		}
+
+		formatCtx->pb = ioCtx;
+
+		if((errcode = avformat_open_input(&formatCtx, "", NULL, NULL)) < 0) {
+			char errDescr[4096];
+			av_strerror(errcode, errDescr, 4096);
+			ALog(@"Error opening file, errcode = %d, error = %s", errcode, errDescr);
+			avformat_close_input(&(formatCtx));
+			buffer = ioCtx->buffer;
+			av_free(ioCtx);
+			av_free(buffer);
+			[source close];
+			source = nil;
+			return [NSArray array];
+		}
+	}
+
+	if((errcode = avformat_find_stream_info(formatCtx, NULL)) < 0) {
+		char errDescr[4096];
+		av_strerror(errcode, errDescr, 4096);
+		ALog(@"Can't find stream info, errcode = %d, error = %s", errcode, errDescr);
+		avformat_close_input(&(formatCtx));
+		if(ioCtx) {
+			buffer = ioCtx->buffer;
+			av_free(ioCtx);
+		}
+		if(buffer) {
+			av_free(buffer);
+		}
+		if(source) {
+			[source close];
+			source = nil;
+		}
+		return [NSArray array];
+	}
+
+	int streamIndex = -1;
+	int metadataIndex = -1;
+	int attachedPicIndex = -1;
+	AVCodecParameters *codecPar;
+
+	for(i = 0; i < formatCtx->nb_streams; i++) {
+		stream = formatCtx->streams[i];
+		codecPar = stream->codecpar;
+		if(streamIndex < 0 && codecPar->codec_type == AVMEDIA_TYPE_AUDIO) {
+			DLog(@"audio codec found");
+			streamIndex = i;
+		} else if(codecPar->codec_id == AV_CODEC_ID_TIMED_ID3) {
+			metadataIndex = i;
+		} else if(stream->disposition & AV_DISPOSITION_ATTACHED_PIC) {
+			attachedPicIndex = i;
+		} else {
+			stream->discard = AVDISCARD_ALL;
+		}
+	}
+
+	if(streamIndex < 0) {
+		ALog(@"no audio codec found");
+		avformat_close_input(&(formatCtx));
+		if(ioCtx) {
+			buffer = ioCtx->buffer;
+			av_free(ioCtx);
+		}
+		if(buffer) {
+			av_free(buffer);
+		}
+		if(source) {
+			[source close];
+			source = nil;
+		}
+		return [NSArray array];
+	}
+
+	NSMutableArray *tracks = [NSMutableArray array];
+
+	int subsongs = formatCtx->nb_chapters;
+	if(subsongs < 1) subsongs = 1;
+
+	for(i = 0; i < subsongs; ++i) {
+		[tracks addObject:[NSURL URLWithString:[[url absoluteString] stringByAppendingFormat:@"#%i", i]]];
+	}
+
+	avformat_close_input(&(formatCtx));
+	if(ioCtx) {
+		buffer = ioCtx->buffer;
+		av_free(ioCtx);
+	}
+	if(buffer) {
+		av_free(buffer);
+	}
+	if(source) {
+		[source close];
+		source = nil;
+	}
+
+	return tracks;
+}
+
+@end

Plugins/FFMPEG/FFMPEGDecoder.h

@@ -13,6 +13,10 @@
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 
+extern int ffmpeg_read(void *opaque, uint8_t *buf, int buf_size);
+extern int ffmpeg_write(void *opaque, uint8_t *buf, int buf_size);
+int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence);
+
 @interface FFMPEGDecoder : NSObject <CogDecoder> {
 	id<CogSource> source;
 	BOOL seekable;
@@ -25,6 +29,9 @@
 	long totalFrames;
 	long framesRead;
 	int bitrate;
+	int subsong;
+	int64_t startTime;
+	int64_t endTime;
 
 	@private
 	unsigned char *buffer;

Plugins/FFMPEG/FFMPEGDecoder.m

@@ -97,6 +97,11 @@ static uint8_t reverse_bits[0x100];
 
 	// register all available codecs
 
+	if([[source.url fragment] length] == 0)
+		subsong = 0;
+	else
+		subsong = [[source.url fragment] intValue];
+
 	NSURL *url = [s url];
 	if(([[url scheme] isEqualToString:@"http"] ||
 	    [[url scheme] isEqualToString:@"https"]) &&
@@ -443,6 +448,14 @@ static uint8_t reverse_bits[0x100];
 		skipSamples = 0;
 	}
 
+	if(subsong < formatCtx->nb_chapters) {
+		AVChapter *chapter = formatCtx->chapters[subsong];
+		startTime = av_rescale_q(chapter->start, chapter->time_base, tb);
+		endTime = av_rescale_q(chapter->end, chapter->time_base, tb);
+		skipSamples = startTime;
+		totalFrames = endTime - startTime;
+	}
+
 	seekFrame = skipSamples; // Skip preroll if necessary
 
 	if(totalFrames < 0)
@@ -537,8 +550,21 @@ static uint8_t reverse_bits[0x100];
 	float _replayGainAlbumPeak = replayGainAlbumPeak;
 	float _replayGainTrackGain = replayGainTrackGain;
 	float _replayGainTrackPeak = replayGainTrackPeak;
-	if(formatCtx->metadata) {
-		while((tag = av_dict_get(formatCtx->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
+	for(size_t i = 0; i < 2; ++i) {
+		AVDictionary *metadata;
+		if(i == 0) {
+			metadata = formatCtx->metadata;
+			if(!metadata) continue;
+		} else {
+			if(subsong < formatCtx->nb_chapters) {
+				metadata = formatCtx->chapters[subsong]->metadata;
+				if(!metadata) continue;
+			} else {
+				break;
+			}
+		}
+		tag = NULL;
+		while((tag = av_dict_get(metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
 			if(!strcasecmp(tag->key, "streamtitle")) {
 				NSString *artistTitle = guess_encoding_of_string(tag->value);
 				NSArray *splitValues = [artistTitle componentsSeparatedByString:@" - "];