When using OBS to stream to YouTube, I set bitrate to CBR
40,000 (40mb/s) and everything works fine. However, when I drop the bitrate to something like 3300, the encoder drops frames when buffer maxes out instead of dropping quality to maintain bitrate. By that, I mean the encoder does actually encode the frames, but they are never uploaded to stream.
I increased the buffer size to try and give it more time to compensate for increased motion. I set buffer size to 100,000; during streams, bitrates would shoot up to 20-25Mb/s (when it's set for 3.3mb/s) and max out the buffer, then drop frames again.
The CBR option is not being ignored. If I set bitrate lower, quality appears to also be lower. I'm not sure what could cause the output bitrate to be so far off from set bitrate.
Settings:
720p 60fps bilinear
CBR
Bitrate: 3300
Buffer size: 3300 (also tried 100,000)
Keyframe interval: Auto (also tried 1, 2, and 3).
Preset: veryfast/faster
Profile: main
VFR: unchecked
Input video (from capture device):
40Mb/s h264 720p 60fps
This also happens when using hardware encoder (AMF VCE) where frame skipping is set to disabled.
Specs: 4.4ghz AMD A10 APU + MSI R7 265 OC 1ghz + 8gb ram
Network: 350mb/s down; 50mb/s up. 3gb/s router.
Before you ask, no it's not the capture card. OBS encodes the frames and chooses not to upload them to keep bitrate limit.
Relavent logs:
40,000 (40mb/s) and everything works fine. However, when I drop the bitrate to something like 3300, the encoder drops frames when buffer maxes out instead of dropping quality to maintain bitrate. By that, I mean the encoder does actually encode the frames, but they are never uploaded to stream.
I increased the buffer size to try and give it more time to compensate for increased motion. I set buffer size to 100,000; during streams, bitrates would shoot up to 20-25Mb/s (when it's set for 3.3mb/s) and max out the buffer, then drop frames again.
The CBR option is not being ignored. If I set bitrate lower, quality appears to also be lower. I'm not sure what could cause the output bitrate to be so far off from set bitrate.
Settings:
720p 60fps bilinear
CBR
Bitrate: 3300
Buffer size: 3300 (also tried 100,000)
Keyframe interval: Auto (also tried 1, 2, and 3).
Preset: veryfast/faster
Profile: main
VFR: unchecked
Input video (from capture device):
40Mb/s h264 720p 60fps
This also happens when using hardware encoder (AMF VCE) where frame skipping is set to disabled.
Specs: 4.4ghz AMD A10 APU + MSI R7 265 OC 1ghz + 8gb ram
Network: 350mb/s down; 50mb/s up. 3gb/s router.
Before you ask, no it's not the capture card. OBS encodes the frames and chooses not to upload them to keep bitrate limit.
Relavent logs:
Code:
00:12:36.234: [x264 encoder: 'streaming_h264'] preset: veryfast
00:12:36.234: [x264 encoder: 'streaming_h264'] settings:
00:12:36.234: rate_control: CBR
00:12:36.234: bitrate: 3300
00:12:36.234: buffer size: 3300
00:12:36.234: crf: 0
00:12:36.234: fps_num: 60000
00:12:36.234: fps_den: 1001
00:12:36.234: width: 1280
00:12:36.234: height: 720
00:12:36.234: keyint: 119
00:12:36.234: vfr: off
00:12:36.234:
00:12:36.234: [x264 encoder: 'streaming_h264'] custom settings: scenecut=0
00:12:36.243: [CoreAudio AAC: 'Track1']: settings:
00:12:36.243: mode: AAC
00:12:36.243: bitrate: 160
00:12:36.243: sample rate: 48000
00:12:36.243: cbr: on
00:12:36.243: output buffer: 1536
00:12:36.244: [rtmp stream: 'adv_stream'] Connecting to RTMP URL rtmp://live-jfk.twitch.tv/app...
00:12:36.299: [rtmp stream: 'adv_stream'] Interface: Qualcomm Atheros AR8171/8175 PCI-E Gigabit Ethernet Controller (NDIS 6.30) (ethernet, 1000 mbps)
00:12:37.837: [rtmp stream: 'adv_stream'] Connection to rtmp://live-jfk.twitch.tv/app successful
00:12:37.841: ==== Streaming Start ===============================================
00:21:16.647: [rtmp stream: 'adv_stream'] User stopped the stream
00:21:16.647: Output 'adv_stream': stopping
00:21:16.647: Output 'adv_stream': Total encoded frames: 31192
00:21:16.647: Output 'adv_stream': Total drawn frames: 31193
00:21:16.648: Output 'adv_stream': Number of lagged frames due to rendering lag/stalls: 5 (0.0%)
00:21:16.654: ==== Streaming Stop ================================================
Last edited: