FFmpeg Input: Support various DSD formats and IFF

Implement support for DFF, WSD, and IFF formats, and all DSD formats
carried within, using our own DSD decimation method instead of relying
on FFmpeg to do it.

Fixes #165

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

Plugins/FFMPEG/FFMPEGDecoder.h

@@ -34,6 +34,11 @@
 	AVCodecContext *codecCtx;
 	AVFrame *lastDecodedFrame;
 	AVPacket *lastReadPacket;
+
+	BOOL rawDSD;
+	BOOL rawDSDReverseBits;
+	BOOL rawDSDPlanar;
+
 	int bytesConsumedFromDecodedFrame;
 	BOOL readNextPacket;
 	int64_t seekFrame;

Plugins/FFMPEG/FFMPEGDecoder.m

@@ -49,10 +49,22 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 
 @implementation FFMPEGDecoder
 
+static uint8_t reverse_bits[0x100];
+
 + (void)initialize {
 	if(self == [FFMPEGDecoder class]) {
 		av_log_set_flags(AV_LOG_SKIP_REPEATED);
 		av_log_set_level(AV_LOG_ERROR);
+
+		for(int i = 0, j = 0; i < 0x100; i++) {
+			reverse_bits[i] = (uint8_t)j;
+			// "reverse-increment" of j
+			for(int bitmask = 0x80;;) {
+				if(((j ^= bitmask) & bitmask) != 0) break;
+				if(bitmask == 1) break;
+				bitmask >>= 1;
+			}
+		}
 	}
 }
 
@@ -79,6 +91,8 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	totalFrames = 0;
 	framesRead = 0;
 
+	rawDSD = NO;
+
 	BOOL isStream = NO;
 
 	// register all available codecs
@@ -184,6 +198,14 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	AVDictionary *dict = NULL;
 
 	switch(codec_id) {
+		case AV_CODEC_ID_DSD_LSBF:
+		case AV_CODEC_ID_DSD_MSBF:
+		case AV_CODEC_ID_DSD_LSBF_PLANAR:
+		case AV_CODEC_ID_DSD_MSBF_PLANAR:
+			rawDSD = YES;
+			rawDSDReverseBits = codec_id == AV_CODEC_ID_DSD_LSBF || codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR;
+			rawDSDPlanar = codec_id == AV_CODEC_ID_DSD_LSBF_PLANAR || codec_id == AV_CODEC_ID_DSD_MSBF_PLANAR;
+			break;
 		case AV_CODEC_ID_MP3:
 			codec = avcodec_find_decoder_by_name("mp3float");
 			break;
@@ -211,7 +233,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 			break;
 	}
 
-	if(!codec)
+	if(!codec && !rawDSD)
 		codec = avcodec_find_decoder(codec_id);
 
 	if(@available(macOS 10.15, *)) {
@@ -229,13 +251,13 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 		}
 	}
 
-	if(!codec) {
+	if(!codec && !rawDSD) {
 		ALog(@"codec not found");
 		av_dict_free(&dict);
 		return NO;
 	}
 
-	if((errcode = avcodec_open2(codecCtx, codec, &dict)) < 0) {
+	if(!rawDSD && (errcode = avcodec_open2(codecCtx, codec, &dict)) < 0) {
 		char errDescr[4096];
 		av_dict_free(&dict);
 		av_strerror(errcode, errDescr, 4096);
@@ -246,7 +268,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	av_dict_free(&dict);
 
 	// Bah, their skipping is broken
-	codecCtx->flags2 |= AV_CODEC_FLAG2_SKIP_MANUAL;
+	if(!rawDSD) codecCtx->flags2 |= AV_CODEC_FLAG2_SKIP_MANUAL;
 
 	lastDecodedFrame = av_frame_alloc();
 	av_frame_unref(lastDecodedFrame);
@@ -256,6 +278,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	bytesConsumedFromDecodedFrame = INT_MAX;
 	seekFrame = -1;
 
+	if(!rawDSD) {
 		frequency = codecCtx->sample_rate;
 		channels = codecCtx->channels;
 		channelConfig = (uint32_t)codecCtx->channel_layout;
@@ -292,6 +315,13 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 			default:
 				return NO;
 		}
+	} else {
+		frequency = codecPar->sample_rate * 8;
+		channels = codecPar->channels;
+		channelConfig = (uint32_t)codecPar->channel_layout;
+		bitsPerSample = 1;
+		floatingPoint = NO;
+	}
 
 	lossy = NO;
 	if(floatingPoint)
@@ -395,6 +425,10 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	endOfStream = NO;
 	endOfAudio = NO;
 
+	if(rawDSD) {
+		totalFrames *= 8;
+	}
+
 	if(!isStream) {
 		if(stream->start_time && stream->start_time != AV_NOPTS_VALUE)
 			skipSamples = av_rescale_q(stream->start_time, stream->time_base, tb);
@@ -533,7 +567,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	if(totalFrames && framesRead >= totalFrames)
 		return 0;
 
-	int frameSize = channels * (bitsPerSample / 8);
+	int frameSize = rawDSD ? channels : channels * (bitsPerSample / 8);
 	int dataSize = 0;
 
 	int bytesToRead = frames * frameSize;
@@ -548,10 +582,16 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	while(bytesRead < bytesToRead) {
 		// buffer size needed to hold decoded samples, in bytes
 		int planeSize;
-		int planar = av_sample_fmt_is_planar(codecCtx->sample_fmt);
+		int planar;
+		if(!rawDSD) {
+			planar = av_sample_fmt_is_planar(codecCtx->sample_fmt);
 			dataSize = av_samples_get_buffer_size(&planeSize, codecCtx->channels,
 			                                      lastDecodedFrame->nb_samples,
 			                                      codecCtx->sample_fmt, 1);
+		} else {
+			planar = 0;
+			dataSize = endOfStream ? 0 : lastReadPacket->size;
+		}
 
 		if(dataSize < 0)
 			dataSize = 0;
@@ -577,6 +617,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 					continue;
 			}
 
+			if(!rawDSD) {
 				if((errcode = avcodec_send_packet(codecCtx, endOfStream ? NULL : lastReadPacket)) < 0) {
 					if(errcode == AVERROR_INVALIDDATA) {
 						ALog(@"Sync error sending packet to codec, attempting to skip it");
@@ -588,6 +629,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 						return 0;
 					}
 				}
+			}
 
 			readNextPacket = NO; // we probably won't need to consume another chunk
 		}
@@ -598,6 +640,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 
 			bytesConsumedFromDecodedFrame = 0;
 
+			if(!rawDSD) {
 				if((errcode = avcodec_receive_frame(codecCtx, lastDecodedFrame)) < 0) {
 					if(errcode == AVERROR_EOF) {
 						endOfAudio = YES;
@@ -618,6 +661,35 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 				dataSize = av_samples_get_buffer_size(&planeSize, codecCtx->channels,
 				                                      lastDecodedFrame->nb_samples,
 				                                      codecCtx->sample_fmt, 1);
+			} else {
+				dataSize = lastReadPacket->size;
+				if(endOfStream) {
+					endOfAudio = YES;
+					break;
+				} else if(dataSize <= bytesConsumedFromDecodedFrame) {
+					readNextPacket = YES;
+					continue;
+				}
+
+				if(rawDSDPlanar) {
+					uint8_t tempBuf[dataSize];
+					size_t samples = dataSize / channels;
+					uint8_t *packetData = lastReadPacket->data;
+					for(size_t i = 0; i < samples; ++i) {
+						for(size_t j = 0; j < channels; ++j) {
+							tempBuf[i * channels + j] = packetData[j * samples + i];
+						}
+					}
+					memmove(packetData, tempBuf, sizeof(tempBuf));
+				}
+
+				if(rawDSDReverseBits) {
+					uint8_t *packetData = lastReadPacket->data;
+					for(size_t i = 0; i < dataSize; ++i) {
+						packetData[i] = reverse_bits[packetData[i]];
+					}
+				}
+			}
 
 			if(dataSize < 0)
 				dataSize = 0;
@@ -647,6 +719,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 			seekBytesSkip -= minSkipped;
 		}
 
+		if(!rawDSD) {
 			int _channels = codecCtx->channels;
 			uint32_t _channelConfig = (uint32_t)codecCtx->channel_layout;
 			float _frequency = codecCtx->sample_rate;
@@ -664,11 +737,14 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 					[self didChangeValueForKey:@"properties"];
 				}
 			}
+		}
 
 		int toConsume = FFMIN((dataSize - bytesConsumedFromDecodedFrame), (bytesToRead - bytesRead));
 
 		// copy decoded samples to Cog's buffer
-		if(!planar || channels == 1) {
+		if(rawDSD) {
+			memmove(targetBuf + bytesRead, (lastReadPacket->data + bytesConsumedFromDecodedFrame), toConsume);
+		} else if(!planar || channels == 1) {
 			memmove(targetBuf + bytesRead, (lastDecodedFrame->data[0] + bytesConsumedFromDecodedFrame), toConsume);
 		} else {
 			uint8_t *out = (uint8_t *)targetBuf + bytesRead;
@@ -685,6 +761,10 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 
 		bytesConsumedFromDecodedFrame += toConsume;
 		bytesRead += toConsume;
+
+		if(rawDSD && bytesConsumedFromDecodedFrame == dataSize) {
+			av_packet_unref(lastReadPacket);
+		}
 	}
 
 	[self updateMetadata];
@@ -708,10 +788,14 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 		endOfAudio = YES;
 		return -1;
 	}
+	if(rawDSD) frame /= 8;
 	AVRational tb = { .num = 1, .den = codecCtx->sample_rate };
 	int64_t ts = av_rescale_q(frame, tb, formatCtx->streams[streamIndex]->time_base);
 	int ret = avformat_seek_file(formatCtx, streamIndex, ts - 1000, ts, ts, 0);
+	if(!rawDSD)
 		avcodec_flush_buffers(codecCtx);
+	else
+		av_packet_unref(lastReadPacket);
 	if(ret < 0) {
 		framesRead = totalFrames;
 		endOfStream = YES;
@@ -721,10 +805,14 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 	readNextPacket = YES; // so we immediately read next packet
 	bytesConsumedFromDecodedFrame = INT_MAX; // so we immediately begin decoding next frame
 	framesRead = frame;
+	if(rawDSD) framesRead *= 8;
 	seekFrame = frame + skipSamples;
 	endOfStream = NO;
 	endOfAudio = NO;
 
+	if(rawDSD)
+		return frame * 8;
+	else
 		return frame;
 }
 
@@ -748,7 +836,7 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 }
 
 + (NSArray *)fileTypes {
-	return @[@"wma", @"asf", @"tak", @"mp4", @"m4a", @"aac", @"mp3", @"mp2", @"m2a", @"mpa", @"ape", @"ac3", @"dts", @"dtshd", @"wav", @"tta", @"vqf", @"vqe", @"vql", @"ra", @"rm", @"rmj", @"mka", @"weba"];
+	return @[@"wma", @"asf", @"tak", @"mp4", @"m4a", @"aac", @"mp3", @"mp2", @"m2a", @"mpa", @"ape", @"ac3", @"dts", @"dtshd", @"wav", @"tta", @"vqf", @"vqe", @"vql", @"ra", @"rm", @"rmj", @"mka", @"weba", @"dff", @"iff", @"dsdiff", @"wsd"];
 }
 
 + (NSArray *)mimeTypes {
@@ -770,7 +858,10 @@ int64_t ffmpeg_seek(void *opaque, int64_t offset, int whence) {
 		@[@"TrueVQ Audio File", @"song.icns", @"vqf", @"vqe", @"vql"],
 		@[@"Real Audio File", @"song.icns", @"ra", @"rm", @"rmj"],
 		@[@"Matroska Audio File", @"song.icns", @"mka"],
-		@[@"WebM Audio File", @"song.icns", @"weba"]
+		@[@"WebM Audio File", @"song.icns", @"weba"],
+		@[@"DSD Stream File", @"song.icns", @"dsf"],
+		@[@"Interchange File Format", @"song.icns", @"iff", @"dsdiff"],
+		@[@"Wideband Single-bit Data", @"song.icns", @"wsd"]
 	];
 }
 

Scripts/ffmpeg-build-arm64.sh

@@ -30,7 +30,7 @@ ADPCM_CODECS=adpcm_4xm,adpcm_adx,adpcm_afx,adpcm_agm,adpcm_aica,adpcm_argo,adpcm
     --enable-swresample\
     --enable-protocol=tcp,tls,http,https,icecast\
     --enable-parser=ac3,mpegaudio,xma,vorbis,opus\
-    --enable-demuxer=hls,mpegts,mpegtsraw,ac3,asf,xwma,mov,oma,ogg,tak,dsf,wav,w64,aac,dts,dtshd,eac3,mp3,bink,flac,msf,xmv,caf,ape,smacker,spdif,mpc,mpc8,rm,matroska,tta,$PCM_CODECS,$ADPCM_CODECS\
+    --enable-demuxer=hls,mpegts,mpegtsraw,ac3,asf,xwma,mov,oma,ogg,tak,dsf,wav,w64,aac,dts,dtshd,eac3,mp3,bink,flac,msf,xmv,caf,ape,smacker,spdif,mpc,mpc8,rm,matroska,tta,dff,wsd,iff,$PCM_CODECS,$ADPCM_CODECS\
     --enable-decoder=ac3,ac3_t,eac3,wmapro,wmav1,wmav2,wmavoice,wmalossless,xma1,xma2,dca,tak,dsd_lsbf,dsd_lsbf_planar,dsd_mbf,dsd_msbf_planar,aac,libfdk_aac,atrac3,atrac3p,mp3float,mp2float,mp1float,bink,binkaudio_dct,binkaudio_rdft,flac,vorbis,ape,smackaud,opus,mpc7,mpc8,alac,cook,tta,$PCM_CODECS,$ADPCM_CODECS\
     --disable-parser=mpeg4video,h263\
     --disable-decoder=mpeg2video,h263,h264,mpeg1video,mpeg2video,mpeg4,hevc,vp9\

Scripts/ffmpeg-build-x86_64.sh

@@ -28,7 +28,7 @@ ADPCM_CODECS=adpcm_4xm,adpcm_adx,adpcm_afx,adpcm_agm,adpcm_aica,adpcm_argo,adpcm
     --enable-swresample\
     --enable-protocol=tcp,tls,http,https,icecast,hls\
     --enable-parser=ac3,mpegaudio,xma,vorbis,opus\
-    --enable-demuxer=hls,mpegts,mpegtsraw,ac3,asf,xwma,mov,oma,ogg,tak,dsf,wav,w64,aac,dts,dtshd,eac3,mp3,bink,flac,msf,xmv,caf,ape,smacker,spdif,mpc,mpc8,rm,matroska,tta,$PCM_CODECS,$ADPCM_CODECS\
+    --enable-demuxer=hls,mpegts,mpegtsraw,ac3,asf,xwma,mov,oma,ogg,tak,dsf,wav,w64,aac,dts,dtshd,eac3,mp3,bink,flac,msf,xmv,caf,ape,smacker,spdif,mpc,mpc8,rm,matroska,tta,dff,wsd,iff,$PCM_CODECS,$ADPCM_CODECS\
     --enable-decoder=ac3,ac3_t,eac3,wmapro,wmav1,wmav2,wmavoice,wmalossless,xma1,xma2,dca,tak,dsd_lsbf,dsd_lsbf_planar,dsd_mbf,dsd_msbf_planar,aac,libfdk_aac,atrac3,atrac3p,mp3float,mp2float,mp1float,bink,binkaudio_dct,binkaudio_rdft,flac,vorbis,ape,smackaud,opus,mpc7,mpc8,alac,cook,tta,$PCM_CODECS,$ADPCM_CODECS\
     --disable-parser=mpeg4video,h263\
     --disable-decoder=mpeg2video,h263,h264,mpeg1video,mpeg2video,mpeg4,hevc,vp9\