From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:47729 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751214AbaI2VXk (ORCPT ); Mon, 29 Sep 2014 17:23:40 -0400 Message-ID: <5429CDD6.9050809@collabora.com> Date: Mon, 29 Sep 2014 17:23:34 -0400 From: Nicolas Dufresne MIME-Version: 1.0 To: linux-media@vger.kernel.org, Hans de Goede Subject: Regression: in v4l2 converter does not set the buffer.length anymore Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: This was initially reported to GStreamer project: https://bugzilla.gnome.org/show_bug.cgi?id=737521 We track this down to be a regression introduced in v4l2-utils from version 1.4.0. In recent GStreamer we make sure the buffer.length field (retreived with QUERYBUF) is bigger or equal to the expected sizeimage (as obtained in S_FMT). This is to fail cleanly and avoid buffer overflow if a driver (or libv4l2) endup doing a short allocation. Since 1.4.0, this field is always 0 if an emulated format is selected. Reverting patch 10213c brings back normal behaviour: http://git.linuxtv.org/cgit.cgi/v4l-utils.git/commit/?id=10213c975afdfcc90aa7de39e66c40cd7e8a57f7 This currently makes use of any emulated format impossible in GStreamer. v4l2-utils 1.4.0 is being shipped at least in debian/unstable at the moment. cheers, Nicolas