[FFmpeg-user] -threads 1 seems not work
For a certain conversion I use '-threads 1'. As I understand it ffmpeg should then only use one CPU. I see that the CPU usage is lower as without this parameter, but it goes up to 180%. So clearly it is using at least two CPU's. Or am I understanding this parameter wrongly? I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a little bit behind to be more stable.) -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: > For a certain conversion I use '-threads 1'. As I understand it ffmpeg > should then only use one CPU. I see that the CPU usage is lower as > without this parameter, but it goes up to 180%. So clearly it is using > at least two CPU's. > Or am I understanding this parameter wrongly? > > I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a > little bit behind to be more stable.) > threads can be used for input decoding, output encoding and filtering. You need to use threads = 1 for all 3 of them. > -- > Cecil Westerhof > Senior Software Engineer > LinkedIn: http://www.linkedin.com/in/cecilwesterhof > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
Paul B Mahol writes: > On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: >> For a certain conversion I use '-threads 1'. As I understand it ffmpeg >> should then only use one CPU. I see that the CPU usage is lower as >> without this parameter, but it goes up to 180%. So clearly it is using >> at least two CPU's. >> Or am I understanding this parameter wrongly? >> >> I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a >> little bit behind to be more stable.) >> > > threads can be used for input decoding, output encoding and filtering. > > You need to use threads = 1 for all 3 of them. I see: -filter_threads -filter_complex_threads But nothing for input decoding and output decoding. By the way: does this mean that ffmpeg can always use 4 CPU's? (input, output, filtering and complex filtering) -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: > Paul B Mahol writes: > >> On 9/12/22, Cecil Westerhof via ffmpeg-user >> wrote: >>> For a certain conversion I use '-threads 1'. As I understand it ffmpeg >>> should then only use one CPU. I see that the CPU usage is lower as >>> without this parameter, but it goes up to 180%. So clearly it is using >>> at least two CPU's. >>> Or am I understanding this parameter wrongly? >>> >>> I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a >>> little bit behind to be more stable.) >>> >> >> threads can be used for input decoding, output encoding and filtering. >> >> You need to use threads = 1 for all 3 of them. > > I see: > -filter_threads > -filter_complex_threads > > But nothing for input decoding and output decoding. > > > By the way: does this mean that ffmpeg can always use 4 CPU's? > (input, output, filtering and complex filtering) No, ffmpeg may use sometimes only 1 or sometimes all available CPUs. That depends on many factors. -threads is both input and output option. > > -- > Cecil Westerhof > Senior Software Engineer > LinkedIn: http://www.linkedin.com/in/cecilwesterhof > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
Paul B Mahol writes: > On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: >> Paul B Mahol writes: >> >>> On 9/12/22, Cecil Westerhof via ffmpeg-user >>> wrote: For a certain conversion I use '-threads 1'. As I understand it ffmpeg should then only use one CPU. I see that the CPU usage is lower as without this parameter, but it goes up to 180%. So clearly it is using at least two CPU's. Or am I understanding this parameter wrongly? I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a little bit behind to be more stable.) >>> >>> threads can be used for input decoding, output encoding and filtering. >>> >>> You need to use threads = 1 for all 3 of them. >> >> I see: >> -filter_threads >> -filter_complex_threads >> >> But nothing for input decoding and output decoding. >> >> >> By the way: does this mean that ffmpeg can always use 4 CPU's? >> (input, output, filtering and complex filtering) > > No, ffmpeg may use sometimes only 1 or sometimes all available CPUs. > That depends on many factors. OK. But that still means it can use three CPU's if it wants to if I have set all three to one? > -threads is both input and output option. -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: > Paul B Mahol writes: > >> On 9/12/22, Cecil Westerhof via ffmpeg-user >> wrote: >>> Paul B Mahol writes: >>> On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: > For a certain conversion I use '-threads 1'. As I understand it ffmpeg > should then only use one CPU. I see that the CPU usage is lower as > without this parameter, but it goes up to 180%. So clearly it is using > at least two CPU's. > Or am I understanding this parameter wrongly? > > I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a > little bit behind to be more stable.) > threads can be used for input decoding, output encoding and filtering. You need to use threads = 1 for all 3 of them. >>> >>> I see: >>> -filter_threads >>> -filter_complex_threads >>> >>> But nothing for input decoding and output decoding. >>> >>> >>> By the way: does this mean that ffmpeg can always use 4 CPU's? >>> (input, output, filtering and complex filtering) >> >> No, ffmpeg may use sometimes only 1 or sometimes all available CPUs. >> That depends on many factors. > > OK. But that still means it can use three CPU's if it wants to if I > have set all three to one? For older versions you currently use that is not true. > >> -threads is both input and output option. > > -- > Cecil Westerhof > Senior Software Engineer > LinkedIn: http://www.linkedin.com/in/cecilwesterhof > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
Am 12.09.22 um 14:38 schrieb Cecil Westerhof via ffmpeg-user: Paul B Mahol writes: On 9/12/22, Cecil Westerhof via ffmpeg-user wrote: For a certain conversion I use '-threads 1'. As I understand it ffmpeg should then only use one CPU. I see that the CPU usage is lower as without this parameter, but it goes up to 180%. So clearly it is using at least two CPU's. Or am I understanding this parameter wrongly? I am using ffmpeg version 4.3.4-0+deb11u1. (Debian always lags a little bit behind to be more stable.) threads can be used for input decoding, output encoding and filtering. You need to use threads = 1 for all 3 of them. I see: -filter_threads -filter_complex_threads But nothing for input decoding and output decoding as always -threads can used twice as other params before the input file it's *always* an input-param and after it it's an output-param ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] -threads 1 seems not work
Am 12.09.22 um 15:00 schrieb Cecil Westerhof via ffmpeg-user: OK. But that still means it can use three CPU's if it wants to if I have set all three to one? following common sense decoding and encoding are at least two threads in total no matter what you do ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
