[FFmpeg-devel] [PATCH v2] librav1e: Don't make users explicitly set -qp -1 to use bit rate mode

James Almer jamrial at gmail.com
Wed Nov 13 19:21:10 EET 2019


On 11/13/2019 2:17 PM, James Almer wrote:
> On 11/13/2019 12:29 PM, Derek Buitenhuis wrote:
>> Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
>> ---
>>  libavcodec/librav1e.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/librav1e.c b/libavcodec/librav1e.c
>> index 5052cac896..a5835ee6be 100644
>> --- a/libavcodec/librav1e.c
>> +++ b/libavcodec/librav1e.c
>> @@ -533,7 +533,7 @@ retry:
>>  #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
>>  
>>  static const AVOption options[] = {
>> -    { "qp", "use constant quantizer mode", OFFSET(quantizer), AV_OPT_TYPE_INT, { .i64 = 100 }, -1, 255, VE },
>> +    { "qp", "use constant quantizer mode (defaults to 100 if no bit rate is set)", OFFSET(quantizer), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 255, VE },
>>      { "speed", "what speed preset to use", OFFSET(speed), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 10, VE },
>>      { "tiles", "number of tiles encode with", OFFSET(tiles), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, INT64_MAX, VE },
>>      { "tile-rows", "number of tiles rows to encode with", OFFSET(tile_rows), AV_OPT_TYPE_INT, { .i64 = 0 }, -1, INT64_MAX, VE },
> 
> LGTM

Actually, remove the comment about what it defaults to. That's out of
our control and may very well change in a future version of librav1e.
libx264 doesn't say anything like that, it just sets qp and crf to -1
and bitrate to 0, and lets the library do its thing, as as we're doing
here after this patch.


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