From 2452f0bbcf3f1420b75ef39c8933f6438b7959d2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tim-Philipp=20M=C3=BCller?= Date: Thu, 23 Dec 2021 01:52:04 +0000 Subject: [PATCH] docs: interlaced video: small additions for alternate interlacing Clarify that width/height in caps is still the frame height/width, not field height width, just like framerate is frame rate not field rate. Part-of: --- .../gst-docs/markdown/additional/design/interlaced-video.md | 6 +++++- .../markdown/additional/design/mediatype-video-raw.md | 5 ++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/subprojects/gst-docs/markdown/additional/design/interlaced-video.md b/subprojects/gst-docs/markdown/additional/design/interlaced-video.md index bc0886d72f..512580492f 100644 --- a/subprojects/gst-docs/markdown/additional/design/interlaced-video.md +++ b/subprojects/gst-docs/markdown/additional/design/interlaced-video.md @@ -119,5 +119,9 @@ Caps for this interlace mode must also carry a `format:Interlaced` caps feature (`GST_CAPS_FEATURE_FORMAT_INTERLACED`) to ensure backwards compatibility for the new mode. -The frame rate in the caps still signals the frame rate, so the notional field +The frame rate in the caps still signals the *frame* rate, so the notional *field* rate will be twice the frame rate from the caps (see `GST_VIDEO_INFO_FIELD_RATE_N`). + +In the same vein the width and height in the caps will indicate *frame* +dimensions not field dimensions, meaning the height of the video data inside +the buffers (1 field) will be half of the height in the caps. diff --git a/subprojects/gst-docs/markdown/additional/design/mediatype-video-raw.md b/subprojects/gst-docs/markdown/additional/design/mediatype-video-raw.md index f638ad6916..b5347a092a 100644 --- a/subprojects/gst-docs/markdown/additional/design/mediatype-video-raw.md +++ b/subprojects/gst-docs/markdown/additional/design/mediatype-video-raw.md @@ -43,7 +43,10 @@ bottom field (`GST_VIDEO_BUFFER_FLAG_BOTTOM_FIELD`). Top and bottom fields are expected to alternate in this mode. Caps for this interlace mode must also carry a `format:Interlaced` caps feature (`GST_CAPS_FEATURE_FORMAT_INTERLACED`) - to ensure backwards compatibility for the new mode (Since: 1.16) + to ensure backwards compatibility for the new mode. `width` and `height` + fields in caps indicate **frame** dimensions not field dimensions, meaning + the height of the video data inside the buffers will be half of the height + in the caps. (Since: 1.16) - **chroma-site**, `G_TYPE_STRING`: Default `GST_VIDEO_CHROMA_SITE_UNKNOWN`. The chroma siting of the video frames.