[FFmpeg-devel] [PATCH] libkvazaar: Set frame rate as a rational number

[Nicolas George]

Le nonidi 29 nivôse, an CCXXIV, Arttu Ylä-Outinen a écrit :
> On 2016-01-16 03:31, Michael Niedermayer wrote:
> 
> >its probably rather unlikely but the multiplication could overflow
> 
> Thanks for taking a look. I attached an updated patch which checks for
> overflow before multiplying.
> 
> - Arttu
> 

> >From 0a8a1a1fffd008d43ec601b7e0a5ed22c2c1f784 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Arttu=20Yl=C3=A4-Outinen?= <arttu.yla-outinen at tut.fi>
> Date: Fri, 15 Jan 2016 13:47:10 +0200
> Subject: [PATCH v2] libkvazaar: Set frame rate as a rational number
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
> 
> Updates libkvazaar to pass the exact frame rate to Kvazaar by setting
> the numerator and denominator separately instead of a single floating
> point number. The exact frame rate is needed for writing timing info to
> the bitstream.
> 
> Requires Kvazaar version 0.8.1.
> 
> Signed-off-by: Arttu Yl??-Outinen <arttu.yla-outinen at tut.fi>
> ---
>  configure               | 2 +-
>  libavcodec/libkvazaar.c | 9 +++++++--
>  2 files changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/configure b/configure
> index cdf07ae..5ee26cf 100755
> --- a/configure
> +++ b/configure
> @@ -5454,7 +5454,7 @@ enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
>                                     check_lib "${gsm_hdr}" gsm_create -lgsm && break;
>                                 done || die "ERROR: libgsm not found"; }
>  enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
> -enabled libkvazaar        && require_pkg_config "kvazaar >= 0.7.1" kvazaar.h kvz_api_get
> +enabled libkvazaar        && require_pkg_config "kvazaar >= 0.8.1" kvazaar.h kvz_api_get
>  enabled libmfx            && require_pkg_config libmfx "mfx/mfxvideo.h" MFXInit
>  enabled libmodplug        && require_pkg_config libmodplug libmodplug/modplug.h ModPlug_Load
>  enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
> diff --git a/libavcodec/libkvazaar.c b/libavcodec/libkvazaar.c
> index e58405d..8cbc4b0 100644
> --- a/libavcodec/libkvazaar.c
> +++ b/libavcodec/libkvazaar.c
> @@ -75,8 +75,13 @@ static av_cold int libkvazaar_init(AVCodecContext *avctx)
>      cfg->width  = avctx->width;
>      cfg->height = avctx->height;
>  
> -    cfg->framerate =
> -      avctx->time_base.den / (double)(avctx->time_base.num * avctx->ticks_per_frame);
> +    if (avctx->ticks_per_frame > INT_MAX / avctx->time_base.num) {
> +        av_log(avctx, AV_LOG_ERROR,
> +               "Could not set framerate for kvazaar: integer overflow\n");

> +        return AVERROR(EOVERFLOW);

EOVERFLOW does not exist on some windows versions. IIRC, we usually use
EINVAL in this kind of case.

> +    }
> +    cfg->framerate_num   = avctx->time_base.den;
> +    cfg->framerate_denom = avctx->time_base.num * avctx->ticks_per_frame;
>      cfg->target_bitrate = avctx->bit_rate;
>      cfg->vui.sar_width  = avctx->sample_aspect_ratio.num;
>      cfg->vui.sar_height = avctx->sample_aspect_ratio.den;

Regards,

-- 
  Nicolas George