Profile 10 Level 5.1 High flags output as Level 5.0

[Former user]

Hi,

In version 1.7.0.474 Windows 64-bit, using Profile 10 Level 5.1 High flags output as Level 5.0, using both float and integer.

Thanks,

Jon

[Ma0]

I've tested ver. 1.7+478

i:\speed\12b>x265vs --profile main10 --level-idc 5.1 720p50_parkrun_ter.y4m w.hevc
y4m  [info]: 1280x720 fps 50/1 i420p8 sar 1:1 frames 0 - 503 of 504
raw  [info]: output file: w.hevc
x265 [info]: HEVC encoder version 1.7+478-365f7ed4d896
x265 [info]: build info [Windows][MSVC 1900][64 bit] 10bit
x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
x265 [warning]: Specifying a decoder level with constant rate factor rate-control requires
x265 [warning]: enabling VBV with vbv-bufsize=40000kb vbv-maxrate=40000kbps. VBV outputs are non-deterministic!
x265 [info]: Main 10 profile, Level-5.1 (Main tier)
x265 [info]: Thread pool created using 4 threads
x265 [info]: frame threads / pool features       : 2 / wpp(12 rows)
x265 [info]: Coding QT: max CU size, min CU size : 64 / 8
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge         : hex / 57 / 2 / 2
x265 [info]: Keyframe min / max / scenecut       : 25 / 250 / 40
x265 [info]: Lookahead / bframes / badapt        : 20 / 4 / 2
x265 [info]: b-pyramid / weightp / weightb       : 1 / 1 / 0
x265 [info]: References / ref-limit  cu / depth  : 3 / 0 / 0
x265 [info]: AQ: mode / str / qg-size / cu-tree  : 1 / 1.0 / 32 / 1
x265 [info]: Rate Control / qCompress            : CRF-28.0 / 0.60
x265 [info]: VBV/HRD buffer / max-rate / init    : 40000 / 40000 / 0.900
x265 [info]: tools: rd=3 psy-rd=0.30 signhide tmvp strong-intra-smoothing
x265 [info]: tools: deblock sao
x265 [info]: frame I:      3, Avg QP:30.34  kb/s: 15604.80
x265 [info]: frame P:    123, Avg QP:34.36  kb/s: 12983.00
x265 [info]: frame B:    378, Avg QP:38.91  kb/s: 460.70
x265 [info]: Weighted P-Frames: Y:0.8% UV:0.8%
x265 [info]: consecutive B-frames: 2.4% 3.2% 10.3% 60.3% 23.8%

encoded 504 frames in 26.93s (18.71 fps), 3606.88 kb/s, Avg QP:37.75

It looks like there is level 5.1.

[Former user]

Thanks for the reply. It seems to change to 5.0 when --high-tier and --vbv-maxrate are specified.

I'm using x265.ru's 64 bit GCC build.

[Steve Borho]

this is deliberate behavior. --level and --high-tier tell the encoder to ensure the bitstream is compatible with that minimum decoder spec. When it signals the stream headers, however, the encoder always signals the lowest level/tier which can decode the bitstream, to maximize the number of devices which can decode the stream.

In Mao's test encode, he is not specifying a target bitrate so CRF is enabled (constant rate factor). When you use CRF and specify a --level, the encoder must enable VBV in order to ensure the bitstream is compliant with that level. So it configures VBV with the max buffer size and max rate allowed by the specified level; thus obviously the bitstream must be signaled with that exact level.

[Steve Borho]

not a bug

[Steve Borho]

see http://x265.readthedocs.org/en/latest/cli.html#profile-level-tier

[Former user]

Thanks for the reply Steve this is very helpful.