您好!
我有疑问。 我已经创建了一个论坛条目("DM385:对于小的 GOP 尺寸、视频流质量差")、我认为这个条目已经解决了。 但我们发现、在非常特殊的视频场景中、我们的视频质量仍然很差。 因此、上次我们只能通过更改配置文件来提高质量、但仍然不是完美的。
我们使用了生成测试图片来提高编码器负载(此图片仍然是编码器1080p @ 60fps 的视频流)。 其效果是、对于如此高的负载上的小 GOP 尺寸、质量会变得更糟。 这种影响似乎与 GOP 尺寸直接相关。 稳定的测试画面恰好根据 GOP 尺寸(请参阅附件)等帧数发生变化、这意味着例如、在 GOP 尺寸为60的情况下、影响每秒发生一次、每秒发生30次、依此类推。 我们还可以看到、这可能发生在某些特殊的"真实"视频场景上、例如 https://www.youtube.com/watch?v=dVkK36KOcqs00:23- 00:40。
我已附加了一些使用所有相同目标位速率80000的不同 GOP 尺寸的视频、这些视频显示了问题。
这里也是我用于生成该样本的编码器配置:
------ 静态参数---
[m3video ]设置 DynamicParams VBR
[m3video ] videnc2Params -> Size : 312.(m3video ] videnc2Params ->大小:312。
[m3video ] videnc2Params -> encodingPreset :3.
[m3video ] videnc2Params -> rateControlPreset :5.
[m3video ] videnc2Params -> maxHeight : 1080/
[m3video ] videnc2Params -> maxWidth : 1920
[m3video] videnc2Params -> dataEndimeas: 1.
[m3video ] videnc2Params -> maxInterFrameInterval:1.
[m3video ] videnc2Params -> maxBitRate :80000
[m3video ] videnc2Params -> minBitRate :0
[m3video ] videnc2Params -> inputChromaFormat :9.
[m3video ] videnc2Params -> inputContentType :0
[m3video ] videnc2Params -> operatingMode :1.
[m3video ] videnc2Params ->配置文件 :77
[m3video ] videnc2Params -> Level :42.
[m3video ] videnc2Params -> inputDataMode :3.
[m3video ] videnc2Params -> outputDataMode :3.
[m3video ] videnc2Params -> numInputDataUnits :1.
[m3video ] videnc2Params -> numOutputDataUnits :1.
------ 动态参数---
[m3视频]
[m3video ]------ CH 0:H264 ENC:动态参数---
[m3视频]
[m3video ] videnc2DynamicParams -> InputHeight :1080
[m3video ] videnc2DynamicParams -> InputWidth :1920
[m3video ] videnc2DynamicParams -> refFrameRate :25000
[m3video ] videnc2DynamicParams -> targetFrameRate :60000
[m3video ] videnc2DynamicParams -> targetBitRate :80000
[m3video ] videnc2DynamicParams -> IntraFrameInterval :5.
[m3video ] videnc2DynamicParams -> generateHeader :0
[m3video ] videnc2DynamicParams -> CaptureWidth :1920
[m3video ] videnc2DynamicParams -> forceFrame :-1
[m3video ] videnc2DynamicParams -> InterFrameInterval :1.
[m3video ] videnc2DynamicParams -> mvAccuracy : 2.
[m3video ] videnc2DynamicParams -> sampleAstioHeight:1.
[m3video ] videnc2DynamicParams -> sampleAstioWidth :1.
[m3video ] videnc2DynamicParams -> ignoreOutbufSizeFlag :1.
[m3video ] videnc2DynamicParams -> lateAcquireArg :-1
[m3视频]
[m3video ] rateControlParams -> rateControlParamsPreset :1.
[m3video ] rateControlParams -> ScalingMatrixPreset :0
[m3video ] rateControlParams -> rcAlgo : 0
[m3video ] rateControlParams -> QPI :-1
[m3video ] rateControlParams -> qpMaxI : 44.
[m3video ] rateControlParams -> qpMinI :8.
[m3video ] rateControlParams -> qpP :-1
[m3video ] rateControlParams -> qpMaxP :44.
[m3video ] rateControlParams -> qpMinP :8.
[m3video ] rateControlParams -> qpOffsetB :4.
[m3video ] rateControlParams -> qpMaxB :44.
[m3video ] rateControlParams -> qpMinB :10.
[m3video ] rateControlParams -> allowFrameSkip :1.
[m3video ] rateControlParams -> removeExpansiveCoeff :0
[m3video ] rateControlParams -> ChromaQPIndexOffset :0
[m3video ] rateControlParams -> IPQualityFactor :0
[m3video ] rateControlParams -> initialBufferLevel :16000000
[m3video ] rateControlParams -> HRDBufferSize : 16000000
[m3video ] rateControlParams -> minPicSizeRatioI :0
[m3video ] rateControlParams -> maxPicSizeRatioI :96
[m3video ] rateControlParams -> minPicSizeRatioP :0
[m3video ] rateControlParams -> maxPicSizeRatioP :0
[m3video ] rateControlParams -> minPicSizeRatioB :0
[m3video ] rateControlParams -> maxPicSizeRatioB :0
[m3video ] rateControlParams -> enablePRC :1.
[m3video ] rateControlParams -> enablePartialFrameSkip :1.
[m3video ] rateControlParams ->丢弃 SavedBits :1.
[m3video ] rateControlParams -> VBRDuration :8.
[m3video ] rateControlParams -> VBRsensivity :0
[m3video ] rateControlParams -> skipDistributionWindowLength : 5.
[m3video ] rateControlParams -> numSkipInDistributionWindow :2.
[m3video ] rateControlParams -> enableHRDComplianceMode :1.
[m3video ] rateControlParams -> frameSkipThMulQ5 :0
[m3video ] rateControlParams -> vbvUseLevelThQ5 :0
[m3视频]
[m3video ] interCodingParams -> InterCodingPreset :0
[m3video ] interCodingParams -> searchRangeHorP :144.
[m3video ] interCodingParams -> searchRangeVerP :32.
[m3video ] interCodingParams -> searchRangeHorB :144.
[m3video ] interCodingParams -> searchRangeVerB :16.
[m3video ] interCodingParams -> InterCodingBias :1.
[m3video ] interCodingParams -> skipMVCodingBias :1.
[m3video ] interCodingParams -> minBlockSizeP :0
[m3video ] interCodingParams -> minBlockSizeB :0
[m3video ] interCodingParams -> meAlgoMode :0
[m3视频]
[M3VIDE] IntraCodingParams -> IntraCodingPreset :0
[m3video ] intraCodingParams -> lumaIntra4x4Enable : 255
[m3video ] intraCodingParams -> lumaIntra8x8启用 :0
[m3video ] intraCodingParams -> lumaIntra16x16Enable : 15.
[m3video ] intraCodingParams ->色度 Intra8x8启用 : 15.
[m3video ] intraCodingParams ->色度分量启用 :1.
[m3video ] intraCodingParams -> intraRefreshMethod :0
[m3video ] intraCodingParams -> intraRefreshRate :0
[m3video ] intraCodingParams -> gdrOverlapRowsBtwFrames : 0
[m3video ] intraCodingParams ->限制 IntraPredEnable:0
[m3video ] intraCodingParams -> intraCodingBias :0
[m3视频]
[m3video ] sliceCodingParams -> sliceCodingPreset :1.
[m3video ] sliceCodingParams -> sliceMode :416
[m3video ] sliceCodingParams -> sliceUnitSize : 416
[m3video ] sliceCodingParams -> sliceStartOffset :[-126 1 2]
[m3video ] sliceCodingParams -> streamFormat :0
[m3视频]
[m3video ] sliceGroupChangeCycle :3072
[m3video ] searchCenter :0
[m3video ] enableStaticMBCount :0
[m3video ] enableROI :262400
[m3视频]
[m3视频]
此致、
Andreas
附件:
采用 GOP 5的测试图片:
e2e.ti.com/.../test_5F00_picture_5F00_gop_5F00_5.mp4
采用 GOP 20的测试图片:
e2e.ti.com/.../test_5F00_picture_5F00_gop_5F00_20.mp4
采用 GOP 60的测试图片:
