On 31.01.2017 04:33, Michael Niedermayer wrote:
On Mon, Jan 30, 2017 at 04:40:17PM +0100, Tobias Rapp wrote:
On 25.01.2017 22:49, Michael Niedermayer wrote:
On Mon, Jan 23, 2017 at 11:12:13AM +0100, Tobias Rapp wrote:
[...]
libavformat/avi.h | 1
libavformat/avienc.c | 77 +++++++++++++++++++++++++++++---
libavformat/version.h | 2
tests/ref/fate/mpeg4-bsf-unpack-bframes | 2
tests/ref/lavf-fate/avi_cram | 2
5 files changed, 74 insertions(+), 10 deletions(-)
8dfa5b4ff26ee67c6772bb257a772672bb91aa34
0002-avformat-avienc-add-reserve_index_space-option.patch
>From 4cc70ffdeb7eeb60e7bbb725bd5885dcacf968d2 Mon Sep 17 00:00:00 2001
From: Tobias Rapp <t.r...@noa-archive.com>
Date: Wed, 4 Jan 2017 15:31:29 +0100
Subject: [PATCH 2/3] avformat/avienc: add reserve_index_space option
Allows the user to reserve space for the ODML master index. A sufficient
sized master index in the AVI header avoids storing follow-up master
indexes within the 'movi' data later.
If the option is omitted or zero the index size is estimated from output
duration and bitrate. A worst-case bitrate for video streams is assumed
in case it is not available.
Note: fate reference files changed because the video stream had zero
bitrate before and is guessed now.
I dont think this is good
if the user app says bitrate is 0 the muxer should not replace that by
the bitrate for a rawvideo stream (when its not rawvideo)
This could be ok for the reserved space calculation but for the file
bitrate, especially with lossy compressed streams this will likely
give values that are less correct than before
My assumption was that bitrate=0 corresponds to "unknown" and that a
large value for MaxBytesPerSec would do less harm than a small/zero
value.
That can be argued about but that should not be in this patch, changing
some bitrates in the header and changing the index space are 2
differnt thigs
I agree. And it would be even better if no guessing would be needed on
muxer level at all because even loss-less encoders would signal the
estimated stream bitrate.
Find attached an updated version of the patch with "worst-case
bitrate guessing" removed.
patch LGTM
Pushed, thanks for the review.
Regards,
Tobias
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