mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Arun Iyengar via B4 Relay <devnull+aiyengar1990.gmail.com@kernel.org>
To: Mauro Carvalho Chehab <mchehab@kernel.org>,
	 Paul Kocialkowski <paulk@sys-base.io>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
	 Nicolas Dufresne <nicolas.dufresne@collabora.com>,
	 Hans Verkuil <hverkuil@kernel.org>,
	Marco Felsch <m.felsch@pengutronix.de>,
	 Michael Tretter <m.tretter@pengutronix.de>,
	 Arun Iyengar <aiyengar1990@gmail.com>
Subject: [PATCH RFC 03/11] media: h264: Write the stateless encode SPS and PPS with nal_ref_idc 3
Date: Tue, 10 Nov 2026 10:05:17 +0000	[thread overview]
Message-ID: <20261110-h264-encode-fixes-v1-3-7a64486df499@gmail.com> (raw)
In-Reply-To: <20261110-h264-encode-fixes-v1-0-7a64486df499@gmail.com>

From: Arun Iyengar <aiyengar1990@gmail.com>

The sequence and picture parameter set NAL units are written with
nal_ref_idc 0, which ITU-T H.264 section 7.4.1 forbids: "nal_ref_idc
shall not be equal to 0 for sequence parameter set or sequence parameter
set extension or subset sequence parameter set or picture parameter set
NAL units". FFmpeg's H.264 probe rejects such streams (an Annex B file
from the encoder is "detected only with low score of 1"), and stricter
decoders may drop the parameter sets.

Write them with nal_ref_idc 3, as other encoders do. Access unit
delimiters keep 0, which the specification requires for them.

Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>
---
 drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c b/drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c
index 2d751855195b..fa5857b77d76 100644
--- a/drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c
+++ b/drivers/media/v4l2-core/v4l2-h264-enc-rbsp.c
@@ -654,7 +654,7 @@ int v4l2_h264_enc_rbsp_sps(struct v4l2_h264_enc_rbsp *rbsp,
 	unsigned int i;
 	int ret;
 
-	ret = v4l2_h264_enc_rbsp_nalu_begin(rbsp, 0, V4L2_H264_NALU_TYPE_SPS);
+	ret = v4l2_h264_enc_rbsp_nalu_begin(rbsp, 3, V4L2_H264_NALU_TYPE_SPS);
 	if (ret)
 		return ret;
 
@@ -845,7 +845,7 @@ int v4l2_h264_enc_rbsp_pps(struct v4l2_h264_enc_rbsp *rbsp,
 	u8 pic_scaling_matrix_present_flag = 0;
 	int ret;
 
-	ret = v4l2_h264_enc_rbsp_nalu_begin(rbsp, 0, V4L2_H264_NALU_TYPE_PPS);
+	ret = v4l2_h264_enc_rbsp_nalu_begin(rbsp, 3, V4L2_H264_NALU_TYPE_PPS);
 	if (ret)
 		return ret;
 

-- 
2.55.0



  parent reply	other threads:[~2026-11-10 10:05 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-10 10:05 [PATCH RFC 00/11] media: h264: Stateless encode core follow-ups: parameter sets, POC type 2, CBR and VBR Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 01/11] media: h264: Only write the SPS and PPS of a stateless encode when they change Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 02/11] media: h264: Support picture order count type 2 in stateless encode Arun Iyengar via B4 Relay
2026-11-10 10:05 ` Arun Iyengar via B4 Relay [this message]
2026-11-10 10:05 ` [PATCH RFC 04/11] media: v4l2-h264-enc-rc: Rework the constant bitrate mode Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 05/11] media: v4l2-core: Move the H.264 encode CBR rate control to a helper Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 06/11] media: v4l2-core: Bound the I picture size in the encode CBR rate control Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 07/11] media: v4l2-core: Halve the I picture QP increase of the encode CBR Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 08/11] media: v4l2-core: Re-encode oversized pictures in " Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 09/11] media: v4l2-core: Fix all-intra streams in the encode CBR rate control Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 10/11] media: v4l2-core: Add a peak bitrate to the encode " Arun Iyengar via B4 Relay
2026-11-10 10:05 ` [PATCH RFC 11/11] media: h264: Add a VBR mode to the stateless " Arun Iyengar via B4 Relay

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20261110-h264-encode-fixes-v1-3-7a64486df499@gmail.com \
    --to=devnull+aiyengar1990.gmail.com@kernel.org \
    --cc=aiyengar1990@gmail.com \
    --cc=hverkuil@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=m.felsch@pengutronix.de \
    --cc=m.tretter@pengutronix.de \
    --cc=mchehab@kernel.org \
    --cc=nicolas.dufresne@collabora.com \
    --cc=paulk@sys-base.io \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®