| Message ID | 20190813010456.91644-1-ffmpeg@tmm1.net |
|---|---|
| State | New |
| Headers | show |
On 13/08/2019 02:04, Aman Gupta wrote: > From: Aman Gupta <aman@tmm1.net> > > This is a regression from 2562dd9e7831743ba6dc5680501fb7d26a2ec62c > which surfaces a pathological bug in some Intel hardware encoders, > causing very low bitrates to be generated whenever VBR mode is used. > > /cc intel/intel-vaapi-driver#480 > > Signed-off-by: Aman Gupta <aman@tmm1.net> > --- > libavcodec/vaapi_encode.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c > index e69b59fa37..231efba6cc 100644 > --- a/libavcodec/vaapi_encode.c > +++ b/libavcodec/vaapi_encode.c > @@ -1665,6 +1665,9 @@ rc_mode_found: > ctx->va_rc_mode = rc_mode->va_mode; > ctx->va_bit_rate = rc_bits_per_second; > > + if (ctx->va_rc_mode == VA_RC_VBR) > + ctx->va_bit_rate = rc_bits_per_second * rc_target_percentage / 100; > + > av_log(avctx, AV_LOG_VERBOSE, "RC mode: %s.\n", rc_mode->name); > if (rc_attr.value == VA_ATTRIB_NOT_SUPPORTED) { > // This driver does not want the RC mode attribute to be set. > The bits_per_second value in the sequence parameters has to match the one in the rate control parameters. That's the max rate value, not the target as modified by target_percentage. For i965, see <https://github.com/intel/intel-vaapi-driver/blob/master/src/i965_encoder.c> (lines 392, 584, 743). When they don't match, it will repeatedly try to change the target bitrate and reset everything. On 13/08/2019 03:42, Fu, Linjie wrote: > > If it's a driver related issue, IMHO we'd better have it fixed in specific driver. This. Thanks, - Mark
diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c index e69b59fa37..231efba6cc 100644 --- a/libavcodec/vaapi_encode.c +++ b/libavcodec/vaapi_encode.c @@ -1665,6 +1665,9 @@ rc_mode_found: ctx->va_rc_mode = rc_mode->va_mode; ctx->va_bit_rate = rc_bits_per_second; + if (ctx->va_rc_mode == VA_RC_VBR) + ctx->va_bit_rate = rc_bits_per_second * rc_target_percentage / 100; + av_log(avctx, AV_LOG_VERBOSE, "RC mode: %s.\n", rc_mode->name); if (rc_attr.value == VA_ATTRIB_NOT_SUPPORTED) { // This driver does not want the RC mode attribute to be set.