Reverse Engineering XAVC-S XML Files

January 3, 2016 4 minute read

Introduction

Many new Sony video cameras (like the FDR-AX100 and HDR-CX900) record into the XAVC-S format. XAVC-S writes to MP4 containers, and alongside them sit nice little XML files with metadata. The following is what I’ve unearthed from poking around the SD card.

This post mainly serves as a log of observations.

Test Setup

The AX100 has three FPS settings when recording to the XAVC-S HD file format (60p, 30p and 24p) and two when recording to XAVS-S 4K (30p and 24p).

For this test there were five shots:

XAVC-S HD, 60 fps
XAVC-S HD, 30 fps
XAVC-S HD, 24 fps
XAVC-S 4K, 30 fps
XAVC-S 4K, 24 fps

MEDIAPRO.XML

This file is located inside the PRIVATE/M4ROOT/ folder and contains a summary of all files on the card and their bitrates. The resolution is inside the videoType attribute i.e. 1920_1080 for HD and 3840_2160 for 4K. Note how @L41 and @L42 seem to indicate 50 Mbps and @L51 indicates 60 Mbps.

<?xml version="1.0" encoding="UTF-8"?>
<MediaProfile xmlns="http://xmlns.sony.net/pro/metadata/mediaprofile" createdAt="2016-01-03T06:10:17-04:00" version="2.10">
	<Properties>
		<System systemId="784B87FFFEBA9815" systemKind="FDR-AX100" masterVersion="XAVC-M4@1.10.00"/>
		<Attached mediaId="1EEAD341907305C09815784B87FFFEBA" mediaKind="AffordableMemoryCard" mediaName=""/>
	</Properties>
	<Contents>
		<Material uri="./CLIP/C0001.MP4" type="MP4" videoType="AVC_1920_1080_HP@L42" audioType="LPCM16" fps="59.94p" dur="210" ch="2" aspectRatio="16:9" offset="0" umid="060A2B340101010501010D43130000004E41F241907305CE784B87FFFEBA9815" status="OK">
			<RelevantInfo uri="./CLIP/C0001M01.XML" type="XML"/>
			<RelevantInfo uri="./THMBNL/C0001T01.JPG" type="JPG"/>
		</Material>
		<Material uri="./CLIP/C0002.MP4" type="MP4" videoType="AVC_1920_1080_HP@L41" audioType="LPCM16" fps="29.97p" dur="165" ch="2" aspectRatio="16:9" offset="0" umid="060A2B340101010501010D431300000008DF1242907305DF784B87FFFEBA9815" status="OK">
			<RelevantInfo uri="./CLIP/C0002M01.XML" type="XML"/>
			<RelevantInfo uri="./THMBNL/C0002T01.JPG" type="JPG"/>
		</Material>
		<Material uri="./CLIP/C0003.MP4" type="MP4" videoType="AVC_1920_1080_HP@L41" audioType="LPCM16" fps="23.98p" dur="120" ch="2" aspectRatio="16:9" offset="0" umid="060A2B340101010501010D4313000000A00A2242907305C0784B87FFFEBA9815" status="OK">
			<RelevantInfo uri="./CLIP/C0003M01.XML" type="XML"/>
			<RelevantInfo uri="./THMBNL/C0003T01.JPG" type="JPG"/>
		</Material>
		<Material uri="./CLIP/C0004.MP4" type="MP4" videoType="AVC_3840_2160_HP@L51" audioType="LPCM16" fps="29.97p" dur="105" ch="2" aspectRatio="16:9" offset="0" umid="060A2B340101010501010D4313000000AEA46349907305C9784B87FFFEBA9815" status="OK">
			<RelevantInfo uri="./CLIP/C0004M01.XML" type="XML"/>
			<RelevantInfo uri="./THMBNL/C0004T01.JPG" type="JPG"/>
		</Material>
		<Material uri="./CLIP/C0005.MP4" type="MP4" videoType="AVC_3840_2160_HP@L51" audioType="LPCM16" fps="23.98p" dur="84" ch="2" aspectRatio="16:9" offset="0" umid="060A2B340101010501010D4313000000B0398149907305CE784B87FFFEBA9815" status="OK">
			<RelevantInfo uri="./CLIP/C0005M01.XML" type="XML"/>
			<RelevantInfo uri="./THMBNL/C0005T01.JPG" type="JPG"/>
		</Material>
	</Contents>
</MediaProfile>

Sidecar XML

These files are located inside PRIVATE/M4ROOT/CLIP and sit alongside the actual XAVC-S MP4 files themselves. Interestingly, only FPS information is present in these sidecar XMLs. Bitrate information is only present in the M4ROOT/MEDIAPRO.XML file!

XAVC-S HD, 60 fps

tcFps="30" halfStep="true" indicates 60 fps (i.e. 30 halved)

<?xml version="1.0" encoding="UTF-8"?>
<NonRealTimeMeta xmlns="urn:schemas-professionalDisc:nonRealTimeMeta:ver.2.00" xmlns:lib="urn:schemas-professionalDisc:lib:ver.2.00" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lastUpdate="2016-01-03T06:10:57-04:00">
	<TargetMaterial umidRef="060A2B340101010501010D43130000004E41F241907305CE784B87FFFEBA9815" status="OK"/>
	<Duration value="210"/>
	<LtcChangeTable tcFps="30" halfStep="true">
		<LtcChange frameCount="0" value="40000000" status="increment"/>
		<LtcChange frameCount="209" value="54830000" status="end"/>
	</LtcChangeTable>
	<CreationDate value="2016-01-03T06:10:57-04:00"/>
	<Device manufacturer="Sony" modelName="FDR-AX100" serialNo="1234567890"/>
	<RecordingMode type="normal" cacheRec="false"/>
</NonRealTimeMeta>

XAVC-S HD, 30 fps

tcFps="30" halfStep="false" indicates 30 fps (i.e. 30 divided by 1)

<?xml version="1.0" encoding="UTF-8"?>
<NonRealTimeMeta xmlns="urn:schemas-professionalDisc:nonRealTimeMeta:ver.2.00" xmlns:lib="urn:schemas-professionalDisc:lib:ver.2.00" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lastUpdate="2016-01-03T06:11:40-04:00">
	<TargetMaterial umidRef="060A2B340101010501010D431300000008DF1242907305DF784B87FFFEBA9815" status="OK"/>
	<Duration value="165"/>
	<LtcChangeTable tcFps="30" halfStep="false">
		<LtcChange frameCount="0" value="40000000" status="increment"/>
		<LtcChange frameCount="164" value="54050000" status="end"/>
	</LtcChangeTable>
	<CreationDate value="2016-01-03T06:11:40-04:00"/>
	<Device manufacturer="Sony" modelName="FDR-AX100" serialNo="1234567890"/>
	<RecordingMode type="normal" cacheRec="false"/>
</NonRealTimeMeta>

XAVC-S HD, 24 fps

tcFps="24" halfStep="false" indicates 24 fps

<?xml version="1.0" encoding="UTF-8"?>
<NonRealTimeMeta xmlns="urn:schemas-professionalDisc:nonRealTimeMeta:ver.2.00" xmlns:lib="urn:schemas-professionalDisc:lib:ver.2.00" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lastUpdate="2016-01-03T06:12:00-04:00">
	<TargetMaterial umidRef="060A2B340101010501010D4313000000A00A2242907305C0784B87FFFEBA9815" status="OK"/>
	<Duration value="120"/>
	<LtcChangeTable tcFps="24" halfStep="false">
		<LtcChange frameCount="0" value="00000000" status="increment"/>
		<LtcChange frameCount="119" value="23040000" status="end"/>
	</LtcChangeTable>
	<CreationDate value="2016-01-03T06:12:00-04:00"/>
	<Device manufacturer="Sony" modelName="FDR-AX100" serialNo="1234567890"/>
	<RecordingMode type="normal" cacheRec="false"/>
</NonRealTimeMeta>

XAVC-S 4K, 30 fps

tcFps="30" halfStep="false" indicates 30 fps, same as before

<?xml version="1.0" encoding="UTF-8"?>
<NonRealTimeMeta xmlns="urn:schemas-professionalDisc:nonRealTimeMeta:ver.2.00" xmlns:lib="urn:schemas-professionalDisc:lib:ver.2.00" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lastUpdate="2016-01-03T06:52:49-04:00">
	<TargetMaterial umidRef="060A2B340101010501010D4313000000AEA46349907305C9784B87FFFEBA9815" status="OK"/>
	<Duration value="105"/>
	<LtcChangeTable tcFps="30" halfStep="false">
		<LtcChange frameCount="0" value="40000000" status="increment"/>
		<LtcChange frameCount="104" value="54030000" status="end"/>
	</LtcChangeTable>
	<CreationDate value="2016-01-03T06:52:49-04:00"/>
	<Device manufacturer="Sony" modelName="FDR-AX100" serialNo="1234567890"/>
	<RecordingMode type="normal" cacheRec="false"/>
</NonRealTimeMeta>

XAVC-S 4K, 24 fps

tcFps="24" halfStep="false" indicates 24 fps, same as before

<?xml version="1.0" encoding="UTF-8"?>
<NonRealTimeMeta xmlns="urn:schemas-professionalDisc:nonRealTimeMeta:ver.2.00" xmlns:lib="urn:schemas-professionalDisc:lib:ver.2.00" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" lastUpdate="2016-01-03T06:53:28-04:00">
	<TargetMaterial umidRef="060A2B340101010501010D4313000000B0398149907305CE784B87FFFEBA9815" status="OK"/>
	<Duration value="84"/>
	<LtcChangeTable tcFps="24" halfStep="false">
		<LtcChange frameCount="0" value="00000000" status="increment"/>
		<LtcChange frameCount="83" value="11030000" status="end"/>
	</LtcChangeTable>
	<CreationDate value="2016-01-03T06:53:28-04:00"/>
	<Device manufacturer="Sony" modelName="FDR-AX100" serialNo="1234567890"/>
	<RecordingMode type="normal" cacheRec="false"/>
</NonRealTimeMeta>

History

[Updated May 14, 2018 with wording changes.]

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