H.261
E695764
H.261 is an early international video compression standard developed by the ITU-T for real-time video conferencing over ISDN and similar networks.
All labels observed (1)
| Label | Occurrences |
|---|---|
| H.261 canonical | 2 |
How this entity was disambiguated
This entity first appeared as the object of triple T7858112 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: H.261 Context triple: [NetMeeting, videoCodec, H.261]
-
A.
H.263
H.263 is a video compression standard developed primarily for low-bitrate communication such as video conferencing and early internet video applications.
-
B.
MPEG-4 Part 2
MPEG-4 Part 2 is a video compression standard used for encoding digital video, notably in early MPEG-4 and DivX/Xvid formats.
-
C.
H.264
H.264 is a widely used video compression standard known for delivering high-quality video at relatively low bitrates, commonly employed in streaming, broadcasting, and video recording.
-
D.
MPEG
MPEG is a family of widely used digital audio and video compression standards developed by the Moving Picture Experts Group for efficient storage and transmission of multimedia content.
-
E.
MPEG-2
MPEG-2 is a widely used digital video and audio compression standard commonly employed for DVDs, digital television broadcasting, and some online video formats.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: H.261 Target entity description: H.261 is an early international video compression standard developed by the ITU-T for real-time video conferencing over ISDN and similar networks.
-
A.
H.263
H.263 is a video compression standard developed primarily for low-bitrate communication such as video conferencing and early internet video applications.
-
B.
MPEG-4 Part 2
MPEG-4 Part 2 is a video compression standard used for encoding digital video, notably in early MPEG-4 and DivX/Xvid formats.
-
C.
H.264
H.264 is a widely used video compression standard known for delivering high-quality video at relatively low bitrates, commonly employed in streaming, broadcasting, and video recording.
-
D.
MPEG
MPEG is a family of widely used digital audio and video compression standards developed by the Moving Picture Experts Group for efficient storage and transmission of multimedia content.
-
E.
MPEG-2
MPEG-2 is a widely used digital video and audio compression standard commonly employed for DVDs, digital television broadcasting, and some online video formats.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
ITU-T Recommendation
ⓘ
video compression standard ⓘ |
| alsoKnownAs | Px64 ⓘ |
| approvedInYear | 1990 ⓘ |
| bitrateRange | 64 kbit/s to 2 Mbit/s multiples of 64 kbit/s ⓘ |
| category | lossy compression ⓘ |
| colorSpace | YCbCr ⓘ |
| compressionType | temporal and spatial redundancy reduction ⓘ |
| designedForNetwork | ISDN NERFINISHED ⓘ |
| developedBy |
CCITT
NERFINISHED
ⓘ
ITU-T NERFINISHED ⓘ |
| domain | digital video coding ⓘ |
| firstPublishedInYear | 1990 ⓘ |
| influenced |
H.263
NERFINISHED
ⓘ
H.264 NERFINISHED ⓘ MPEG-1 Video NERFINISHED ⓘ MPEG-2 Video NERFINISHED ⓘ |
| intendedUseCase | real-time interactive communication ⓘ |
| latencyCharacteristic | low-latency coding suitable for conversational services ⓘ |
| primaryUseEra | 1990s ⓘ |
| region | international standard ⓘ |
| replacedBy |
H.263
NERFINISHED
ⓘ
H.264 NERFINISHED ⓘ |
| scanFormat | interlaced video support via progressive source coding tools ⓘ |
| standardizedBy | ITU-T Study Group 15 NERFINISHED ⓘ |
| standardNumber | ITU-T Recommendation H.261 NERFINISHED ⓘ |
| status | largely obsolete ⓘ |
| supportsAudioAssociation | often used with ISDN audio codecs in conferencing systems ⓘ |
| supportsBitrateMultiple | p x 64 kbit/s ⓘ |
| supportsChromaFormat | 4:2:0 planar ⓘ |
| supportsColorSampling | 4:2:0 ⓘ |
| supportsErrorResilienceFeatures | limited compared to later standards ⓘ |
| supportsFrameRate | up to 30 frames per second ⓘ |
| supportsPictureFormat |
CIF 352x288
ⓘ
QCIF 176x144 ⓘ |
| supportsResolution |
CIF
NERFINISHED
ⓘ
QCIF ⓘ |
| targetApplication |
video conferencing
ⓘ
video telephony ⓘ |
| usesBlockSize | 8x8 DCT blocks ⓘ |
| usesCompressionType | block-based hybrid video coding ⓘ |
| usesEntropyCoding | variable-length coding ⓘ |
| usesGOPStructure | sequences of intra and inter pictures ⓘ |
| usesMacroblockStructure | 16x16 luma macroblocks ⓘ |
| usesMotionCompensation | inter-frame motion-compensated prediction ⓘ |
| usesPictureTypes |
inter-coded pictures
ⓘ
intra-coded pictures ⓘ |
| usesTransform | discrete cosine transform ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: H.261 Description of subject: H.261 is an early international video compression standard developed by the ITU-T for real-time video conferencing over ISDN and similar networks.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.