From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F2CDC3F2D7 for ; Thu, 5 Mar 2020 20:15:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B10C207FD for ; Thu, 5 Mar 2020 20:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726358AbgCEUPm convert rfc822-to-8bit (ORCPT ); Thu, 5 Mar 2020 15:15:42 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:59160 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726173AbgCEUPm (ORCPT ); Thu, 5 Mar 2020 15:15:42 -0500 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 4419728B941; Thu, 5 Mar 2020 20:15:39 +0000 (GMT) Date: Thu, 5 Mar 2020 21:15:35 +0100 From: Boris Brezillon To: Nicolas Dufresne Cc: Mauro Carvalho Chehab , Ezequiel Garcia , linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Rob Herring , Tomasz Figa , kernel@collabora.com, Paul Kocialkowski , Jonas Karlman , Heiko Stuebner , Sakari Ailus , Hans Verkuil Subject: Re: [PATCH v6 2/6] media: v4l2-core: Add helpers to build the H264 P/B0/B1 reflists Message-ID: <20200305211535.2e9a6673@collabora.com> In-Reply-To: References: <20200220163016.21708-1-ezequiel@collabora.com> <20200220163016.21708-3-ezequiel@collabora.com> <20200302142433.0ad1b383@coco.lan> <20200302154426.5fb09f91@collabora.com> Organization: Collabora X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 05 Mar 2020 14:42:34 -0500 Nicolas Dufresne wrote: > Le lundi 02 mars 2020 à 15:44 +0100, Boris Brezillon a écrit : > > On Mon, 2 Mar 2020 14:24:33 +0100 > > Mauro Carvalho Chehab wrote: > > > > > Em Thu, 20 Feb 2020 13:30:12 -0300 > > > Ezequiel Garcia escreveu: > > > > > > > From: Boris Brezillon > > > > > > > > Building those list is a standard procedure described in section > > > > '8.2.4 Decoding process for reference picture lists construction' of > > > > the H264 specification. > > > > > > > > We already have 2 drivers needing the same logic (hantro and rkvdec) and > > > > I suspect we will soon have more. > > > > > > > > Let's provide generic helpers to create those lists. > > > > > > > > Signed-off-by: Boris Brezillon > > > > Signed-off-by: Ezequiel Garcia > > > > --- > > > > drivers/media/v4l2-core/Kconfig | 4 + > > > > drivers/media/v4l2-core/Makefile | 1 + > > > > drivers/media/v4l2-core/v4l2-h264.c | 258 ++++++++++++++++++++++++++++ > > > > include/media/v4l2-h264.h | 85 +++++++++ > > > > 4 files changed, 348 insertions(+) > > > > create mode 100644 drivers/media/v4l2-core/v4l2-h264.c > > > > create mode 100644 include/media/v4l2-h264.h > > > > > > > > diff --git a/drivers/media/v4l2-core/Kconfig b/drivers/media/v4l2- > > > > core/Kconfig > > > > index 39e3fb30ba0b..8a4ccfbca8cf 100644 > > > > --- a/drivers/media/v4l2-core/Kconfig > > > > +++ b/drivers/media/v4l2-core/Kconfig > > > > @@ -45,6 +45,10 @@ config VIDEO_PCI_SKELETON > > > > config VIDEO_TUNER > > > > tristate > > > > > > > > +# Used by drivers that need v4l2-h264.ko > > > > +config V4L2_H264 > > > > + tristate > > > > + > > > > # Used by drivers that need v4l2-mem2mem.ko > > > > config V4L2_MEM2MEM_DEV > > > > tristate > > > > diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2- > > > > core/Makefile > > > > index 786bd1ec4d1b..c5c53e0941ad 100644 > > > > --- a/drivers/media/v4l2-core/Makefile > > > > +++ b/drivers/media/v4l2-core/Makefile > > > > @@ -21,6 +21,7 @@ obj-$(CONFIG_VIDEO_V4L2) += v4l2-dv-timings.o > > > > obj-$(CONFIG_VIDEO_TUNER) += tuner.o > > > > > > > > obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o > > > > +obj-$(CONFIG_V4L2_H264) += v4l2-h264.o > > > > > > > > obj-$(CONFIG_V4L2_FLASH_LED_CLASS) += v4l2-flash-led-class.o > > > > > > > > diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2- > > > > core/v4l2-h264.c > > > > new file mode 100644 > > > > index 000000000000..4f68c27ec7fd > > > > --- /dev/null > > > > +++ b/drivers/media/v4l2-core/v4l2-h264.c > > > > @@ -0,0 +1,258 @@ > > > > +// SPDX-License-Identifier: GPL-2.0 > > > > +/* > > > > + * V4L2 H264 helpers. > > > > + * > > > > + * Copyright (C) 2019 Collabora, Ltd. > > > > + * > > > > + * Author: Boris Brezillon > > > > + */ > > > > + > > > > +#include > > > > +#include > > > > + > > > > +#include > > > > + > > > > +/** > > > > + * v4l2_h264_init_reflist_builder() - Initialize a P/B0/B1 reference list > > > > + * builder > > > > + * > > > > + * @b: the builder context to initialize > > > > + * @dec_params: decode parameters control > > > > + * @slice_params: first slice parameters control > > > > + * @sps: SPS control > > > > + * @dpb: DPB to use when creating the reference list > > > > + */ > > > > +void > > > > +v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b, > > > > + const struct v4l2_ctrl_h264_decode_params *dec_params, > > > > + const struct v4l2_ctrl_h264_slice_params *slice_params, > > > > + const struct v4l2_ctrl_h264_sps *sps, > > > > + const struct v4l2_h264_dpb_entry *dpb) > > > > > > The prototype here is not nice... > > > > > > > +{ > > > > + int cur_frame_num, max_frame_num; > > > > + unsigned int i; > > > > + > > > > + max_frame_num = 1 << (sps->log2_max_frame_num_minus4 + 4); > > > > + cur_frame_num = slice_params->frame_num; > > > > + > > > > + memset(b, 0, sizeof(*b)); > > > > + if (!(slice_params->flags & V4L2_H264_SLICE_FLAG_FIELD_PIC)) > > > > + b->cur_pic_order_count = min(dec_params->bottom_field_order_cnt, > > > > + dec_params->top_field_order_cnt); > > > > + else if (slice_params->flags & V4L2_H264_SLICE_FLAG_BOTTOM_FIELD) > > > > + b->cur_pic_order_count = dec_params->bottom_field_order_cnt; > > > > + else > > > > + b->cur_pic_order_count = dec_params->top_field_order_cnt; > > > > + > > > > + for (i = 0; i < 16; i++) { > > > > + u32 pic_order_count; > > > > + > > > > + if (!(dpb[i].flags & V4L2_H264_DPB_ENTRY_FLAG_ACTIVE)) > > > > + continue; > > > > + > > > > + b->refs[i].pic_num = dpb[i].pic_num; > > > > > > ... as you're expecting a fixed number of elements at DPB array, and using > > > a magic number (16) inside the for loop. > > > > I used to have a '#define V4L2_H264_NUM_DPB_ENTRIES 16' but have been > > told that this is an arbitrary limitation (the spec does not explicitly > > limit the DPB size, even if all the HW we've seen seem to limit it to > > 16). Maybe we can pass the DPB array size as an argument so it stays > > HW-specific. > > it's formalized in A.31 h), to quote it: > > max_dec_frame_buffering <= MaxDpbFrames, where MaxDpbFrames is equal to > > Min( MaxDpbMbs / ( PicWidthInMbs * FrameHeightInMbs ), 16 ) > > So a DPB larger then this is not an H.24 DPB. My bad, I mixed "max number of slices per frame" and "max number of entries in the DPB". The first one I couldn't find a clear answer to, while the second one has been 16 from the start. Sorry for the confusion.