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c13d959343
This change improves the performance and multicore scalability of the vp9 codec for streaming single-pass encoded videos by taking advantage of up to 64 cores in the system. The current thread limit for ffmpeg codecs is 16 (MAX_AUTO_THREADS in pthread_internal.h) due to a limitation in H.264 codec that prevents more than 16 threads being used. Experiments show that increasing the thread limit to 64 for vp9 improves the performance for encoding 4K raw videos for streaming by up to 47% compared to 16 threads, and from 20-30% for 32 threads, with the same quality as measured by the VMAF score. Rationale for this change: Vp9 uses tiling to split the video frame into multiple columns; tiles must be at least 256 pixels wide, so there is a limit to how many tiles can be used. The tiles can be processed in parallel, and more tiles mean more CPU threads can be used. 4K videos can make use of 16 threads, and 8K videos can use 32. Row-mt can double the number of threads so 64 threads can be used. Signed-off-by: James Zern <jzern@google.com>
37 lines
1.1 KiB
C
37 lines
1.1 KiB
C
/*
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* Copyright (c) 2013 Guillaume Martres <smarter@ubuntu.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVCODEC_LIBVPX_H
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#define AVCODEC_LIBVPX_H
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#include <vpx/vpx_codec.h>
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#include "codec_internal.h"
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#define MAX_VPX_THREADS 64
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void ff_vp9_init_static(FFCodec *codec);
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#if 0
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enum AVPixelFormat ff_vpx_imgfmt_to_pixfmt(vpx_img_fmt_t img);
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vpx_img_fmt_t ff_vpx_pixfmt_to_imgfmt(enum AVPixelFormat pix);
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#endif
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#endif /* AVCODEC_LIBVPX_H */
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