[FFmpeg-devel] [PATCH v1 3/3] swscale/la: Add output_lasx.c file.

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Wed Sep 21 13:50:12 EEST 2022


Shiyou Yin:
> 
> 
>> 2022年9月11日 10:06,Shiyou Yin <yinshiyou-hf at loongson.cn> 写道:
>>
>>
>>
>>> 2022年9月9日 21:11,Andreas Rheinhardt <andreas.rheinhardt at outlook.com <mailto:andreas.rheinhardt at outlook.com>> 写道:
>>>
>>> Shiyou Yin:
>>>>
>>>>
>>>>> 2022年9月6日 16:12,Shiyou Yin <yinshiyou-hf at loongson.cn <mailto:yinshiyou-hf at loongson.cn>> 写道:
>>>>>
>>>>>>
>>>>>> 2022年8月29日 20:30,Andreas Rheinhardt <andreas.rheinhardt at outlook.com <mailto:andreas.rheinhardt at outlook.com> <mailto:andreas.rheinhardt at outlook.com <mailto:andreas.rheinhardt at outlook.com>>> 写道:
>>>>>>
>>>>>> Hao Chen:
>>>>>>> ffmpeg -i ~/media/1_h264_1080p_30fps_3Mbps.mp4 -f rawvideo -s 640x480 -pix_fmt
>>>>>>> rgb24 -y /dev/null -an
>>>>>>> before: 150fps
>>>>>>> after: 183fps
>>>>>>>
>>>>>>> Signed-off-by: Hao Chen <chenhao at loongson.cn <mailto:chenhao at loongson.cn>>
>>>>>>> ---
>>>>>>> libswscale/loongarch/Makefile | 3 +-
>>>>>>> libswscale/loongarch/output_lasx.c | 1982 +++++++++++++++++
>>>>>>> libswscale/loongarch/swscale_init_loongarch.c | 3 +
>>>>>>> libswscale/loongarch/swscale_loongarch.h | 6 +
>>>>>>> 4 files changed, 1993 insertions(+), 1 deletion(-)
>>>>>>> create mode 100644 libswscale/loongarch/output_lasx.c
>>>>>>>
>>>>
>>>>>>> +static void
>>>>>>> +yuv2rgb_2_template_lasx(SwsContext *c, const int16_t *buf[2],
>>>>>>> + const int16_t *ubuf[2], const int16_t *vbuf[2],
>>>>>>> + const int16_t *abuf[2], uint8_t *dest, int dstW,
>>>>>>> + int yalpha, int uvalpha, int y,
>>>>>>> + enum AVPixelFormat target, int hasAlpha)
>>>>>>> +{
>>>>>>> + const int16_t *buf0 = buf[0], *buf1 = buf[1],
>>>>>>> + *ubuf0 = ubuf[0], *ubuf1 = ubuf[1],
>>>>>>> + *vbuf0 = vbuf[0], *vbuf1 = vbuf[1];
>>>>>>> + int yalpha1 = 4096 - yalpha;
>>>>>>> + int uvalpha1 = 4096 - uvalpha;
>>>>>>> + int i, count = 0;
>>>>>>> + int len = dstW - 15;
>>>>>>> + int len_count = (dstW + 1) >> 1;
>>>>>>> + const void *r, *g, *b;
>>>>>>> + int head = YUVRGB_TABLE_HEADROOM;
>>>>>>> + __m256i v_yalpha1 = __lasx_xvreplgr2vr_w(yalpha1);
>>>>>>> + __m256i v_uvalpha1 = __lasx_xvreplgr2vr_w(uvalpha1);
>>>>>>> + __m256i v_yalpha = __lasx_xvreplgr2vr_w(yalpha);
>>>>>>> + __m256i v_uvalpha = __lasx_xvreplgr2vr_w(uvalpha);
>>>>>>> + __m256i headroom = __lasx_xvreplgr2vr_w(head);
>>>>>>> +
>>>>>>> + for (i = 0; i < len; i += 16) {
>>>>>>> + int Y1, Y2, U, V;
>>>>>>> + int i_dex = i << 1;
>>>>>>> + int c_dex = count << 1;
>>>>>>> + __m256i y0_h, y0_l, y0, u0, v0;
>>>>>>> + __m256i y1_h, y1_l, y1, u1, v1;
>>>>>>> + __m256i y_l, y_h, u, v;
>>>>>>> +
>>>>>>> + DUP4_ARG2(__lasx_xvldx, buf0, i_dex, ubuf0, c_dex, vbuf0, c_dex,
>>>>>>> + buf1, i_dex, y0, u0, v0, y1);
>>>>>>> + DUP2_ARG2(__lasx_xvldx, ubuf1, c_dex, vbuf1, c_dex, u1, v1);
>>>>>>> + DUP2_ARG2(__lasx_xvsllwil_w_h, y0, 0, y1, 0, y0_l, y1_l);
>>>>>>> + DUP2_ARG1(__lasx_xvexth_w_h, y0, y1, y0_h, y1_h);
>>>>>>> + DUP4_ARG1(__lasx_vext2xv_w_h, u0, u1, v0, v1, u0, u1, v0, v1);
>>>>>>> + y0_l = __lasx_xvmul_w(y0_l, v_yalpha1);
>>>>>>> + y0_h = __lasx_xvmul_w(y0_h, v_yalpha1);
>>>>>>> + u0 = __lasx_xvmul_w(u0, v_uvalpha1);
>>>>>>> + v0 = __lasx_xvmul_w(v0, v_uvalpha1);
>>>>>>> + y_l = __lasx_xvmadd_w(y0_l, v_yalpha, y1_l);
>>>>>>> + y_h = __lasx_xvmadd_w(y0_h, v_yalpha, y1_h);
>>>>>>> + u = __lasx_xvmadd_w(u0, v_uvalpha, u1);
>>>>>>> + v = __lasx_xvmadd_w(v0, v_uvalpha, v1);
>>>>>>> + y_l = __lasx_xvsrai_w(y_l, 19);
>>>>>>> + y_h = __lasx_xvsrai_w(y_h, 19);
>>>>>>> + u = __lasx_xvsrai_w(u, 19);
>>>>>>> + v = __lasx_xvsrai_w(v, 19);
>>>>>>> + u = __lasx_xvadd_w(u, headroom);
>>>>>>> + v = __lasx_xvadd_w(v, headroom);
>>>>>>> + WRITE_YUV2RGB(y_l, y_l, u, v, 0, 1, 0, 0);
>>>>>>> + WRITE_YUV2RGB(y_l, y_l, u, v, 2, 3, 1, 1);
>>>>>>> + WRITE_YUV2RGB(y_h, y_h, u, v, 0, 1, 2, 2);
>>>>>>> + WRITE_YUV2RGB(y_h, y_h, u, v, 2, 3, 3, 3);
>>>>>>> + WRITE_YUV2RGB(y_l, y_l, u, v, 4, 5, 4, 4);
>>>>>>> + WRITE_YUV2RGB(y_l, y_l, u, v, 6, 7, 5, 5);
>>>>>>> + WRITE_YUV2RGB(y_h, y_h, u, v, 4, 5, 6, 6);
>>>>>>> + WRITE_YUV2RGB(y_h, y_h, u, v, 6, 7, 7, 7);
>>>>>>> + }
>>>>>>> + if (dstW - i >= 8) {
>>>>>>> + int Y1, Y2, U, V;
>>>>>>> + int i_dex = i << 1;
>>>>>>> + __m256i y0_l, y0, u0, v0;
>>>>>>> + __m256i y1_l, y1, u1, v1;
>>>>>>> + __m256i y_l, u, v;
>>>>>>> +
>>>>>>> + y0 = __lasx_xvldx(buf0, i_dex);
>>>>>>
>>>>>> 1. Not long ago, I tried to constify the src pointer of several asm
>>>>>> functions and noticed that they produced new warnings for loongarch
>>>>>> (according to patchwork:
>>>>>> https://patchwork.ffmpeg.org/project/ffmpeg/patch/DB6PR0101MB2214178D3E6B8DCA5B86F8198F9A9@DB6PR0101MB2214.eurprd01.prod.exchangelabs.com/ <https://patchwork.ffmpeg.org/project/ffmpeg/patch/DB6PR0101MB2214178D3E6B8DCA5B86F8198F9A9@DB6PR0101MB2214.eurprd01.prod.exchangelabs.com/>),
>>>>>> even though I was sure that the code is const-correct. After finding
>>>>>> (via https://github.com/opencv/opencv/pull/21833 <https://github.com/opencv/opencv/pull/21833>) a toolchain
>>>>>> (https://gitee.com/wenux/cross-compiler-la-on-x86 <https://gitee.com/wenux/cross-compiler-la-on-x86>) that can build the
>>>>>> lasx and lsx code (upstream GCC seems to be lacking lsx and lasx support
>>>>>> at the moment; at least, my self-compiled loongarch-GCC did not support
>>>>>> lsx and lasx) the issue was clear: lsxintrin.h and lasxintrin.h do not
>>>>>> use const at all, even for functions that only read data (I presume the
>>>>>> vl in __lsx_vldx stands for "vector load"?).
>>>>>> So I sent another iteration
>>>>>> https://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299562.html <https://ffmpeg.org/pipermail/ffmpeg-devel/2022-August/299562.html> of
>>>>>> that patchset that now added wrappers for __lsx_vldx() and
>>>>>> __lasx_xvldx() and cc'ed you and some other developers from loongson to
>>>>>> alert you of the issue in the hope that you fix the headers, so that my
>>>>>> wrappers wouldn't need to be applied. That didn't work, as my mails
>>>>>> could not be delivered to you. So I applied the patchset.
>>>>>> 2. You use __lasx_xvldx() to read from a const int16_t. This will give
>>>>>> new warnings unless the above issue has been fixed. Has it?
>>>>>> 3. I don't know whether it has, as patchwork's fate tests don't work for
>>>>>> a few days already. Given that the mails I receive from patchwork when
>>>>>> it doesn't like a commit message arrive from "Patchwork
>>>>>> <yinshiyou-hf at loongson.cn <mailto:yinshiyou-hf at loongson.cn>>" I presume that loongson is now somehow
>>>>>> running patchwork, so you should be able to inform the right people to
>>>>>> fix it.
>>>>>> 4. If you fixed the const-issue, can you please make an updated
>>>>>> toolchain with lsx and lasx support enabled available to us?
>>>>>>
>>>>>> - Andreas
>>>>>>
>>>>>
>>>>> Hi Andreas,
>>>>>
>>>>> Sorry for the late reply.
>>>>> This issue will be fixed by using const for v1 of __lsx_vldx, and I will update toolchain of LoongArch patchwork runner ASAP.
>>>>> Thank you very much for analyzing this problem and giving suggestion. 
>>>>>
>>>>> Thanks,
>>>>> Shiyou
>>>>
>>>> Hi Andreas,
>>>> Has updated patchwork runner environment, you can revert the patchset which add wrappers for __lsx_[x]vldx.
>>>>
>>>
>>> Just sent the patches:
>>> https://ffmpeg.org/pipermail/ffmpeg-devel/2022-September/301201.html <https://ffmpeg.org/pipermail/ffmpeg-devel/2022-September/301201.html>
>>> Can you provide an updated toolchain (with x86 host) able to compile lsx
>>> and lasx?
>>>
>>> - Andreas
>>
>> Compiler team haven’t release this version yet(maybe at Sep 13), you can check here :
>> http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/ <http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/>
>> If you want to try it now, you can update attachment file first.
>>
>>
> toolchain has been uploaded to http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/ <http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/>
> loongson-gnu-toolchain-8.3-src-loongarch64-linux-gnu-rc1.1.tar <http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/loongson-gnu-toolchain-8.3-src-loongarch64-linux-gnu-rc1.1.tar>  
> loongson-gnu-toolchain-8.3-x86_64-loongarch64-linux-gnu-rc1.1.tar.xz <http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/loongson-gnu-toolchain-8.3-x86_64-loongarch64-linux-gnu-rc1.1.tar.xz>
> loongson-gnu-toolchain-8.3-x86_64-loongarch64-linux-gnu-rc1.1.tar.xz.md5 <http://ftp.loongnix.cn/toolchain/gcc/release/loongarch/gcc8/loongson-gnu-toolchain-8.3-x86_64-loongarch64-linux-gnu-rc1.1.tar.xz.md5>  
> 
> Thanks,
> Shiyou

Yes, I have already noticed this and have therefore already reverted my
wrapper patches. Thanks.

- Andreas


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