Question / Help x264 causes fluctuating bitrate while Nvenc makes stream beautiful

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PracticeAcc0unt

New Member
Hey, sorry if this has been posted I have spent weeks looking for this answer. My upload is between 4.2 and 5mbps. Within the last 2 months my obs has gone from using x264 at 1500 bitrate with clear stream to the same settings but my bitrate jumps up and down as soon as I start stream. I have tried different bitrates, different scaling, different resolutions, different streaming services, opening ports, contacting ISP. Nothing has helped. Today I got a wild hare to try and use Nvenc as the encoder and guess what. Bitrate at 3000 the stream looks beautiful and runs smooth. My bitrate still changes a tiny bit here and there but no where near as much as it does when using x264. I use a 2 pc stream setup in which I cast my video and audio to my streaming pc via lan and then stream it from the streaming pc. I guess my question is why is x264 recommended but I can only stream with Nvenc? My streaming pc has an i7 4400 and a gtx 965.
 
Even with NVEnc, you had .8 to 1% of frames not make it. Which isn't great. But yeah, it does seem better than x264. To be fair, only 1 of the 3 times you used x264, did you use the same bitrate as your NVEnc attempts, the other times were more. Here's the 1 time:
13:16:01.596: [x264 encoder: 'streaming_h264'] preset: veryfast
13:16:01.596: [x264 encoder: 'streaming_h264'] profile: main
13:16:01.613: [x264 encoder: 'streaming_h264'] settings:
13:16:01.613: rate_control: CBR
13:16:01.613: bitrate: 2800
13:16:01.613: buffer size: 2800
13:16:01.613: crf: 0
13:16:01.613: fps_num: 30
13:16:01.613: fps_den: 1
13:16:01.613: width: 1280
13:16:01.613: height: 720
13:16:01.613: keyint: 250
13:16:01.613:
13:16:01.634: [CoreAudio AAC: 'Track1']: settings:
13:16:01.634: mode: AAC
13:16:01.634: bitrate: 160
13:16:01.634: sample rate: 44100
13:16:01.634: cbr: on
13:16:01.634: output buffer: 1536
13:16:01.635: [rtmp stream: 'adv_stream'] Connecting to RTMP URL rtmp://live-dfw.twitch.tv/app...
13:16:01.664: [rtmp stream: 'adv_stream'] Interface: Realtek PCIe GBE Family Controller (ethernet, 1000 mbps)
13:16:02.571: [rtmp stream: 'adv_stream'] Connection to rtmp://live-dfw.twitch.tv/app successful
13:16:02.577: ==== Streaming Start ===============================================
13:25:23.012: [rtmp stream: 'adv_stream'] User stopped the stream
13:25:23.012: Output 'adv_stream': stopping
13:25:23.012: Output 'adv_stream': Total frames output: 16045 (16785 attempted)
13:25:23.012: Output 'adv_stream': Total drawn frames: 16841
13:25:23.012: Output 'adv_stream': Number of dropped frames due to insufficient bandwidth/connection stalls: 740 (4.4%)
13:25:23.016: ==== Streaming Stop ================================================
Click to expand...

4.4% dropped frames is going to look pretty bad. I still say you need to use a custom buffer size and set it to something lower, perhaps half the bitrate. And I'd suggest lowering your overall bitrate too, even NVEnc is dropping too many frames at 2800kbps. Try 2500 with 1250 buffer.
 
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