[FFmpeg-devel] [PATCH 2/2] avcodec/mjpegdec: add support for frame threading

Paul B Mahol onemda at gmail.com
Thu Sep 7 20:28:08 EEST 2023


On Thu, Sep 7, 2023 at 7:17 PM Paul B Mahol <onemda at gmail.com> wrote:

>
>
> On Tue, Dec 6, 2022 at 12:02 AM Timo Rothenpieler <timo at rothenpieler.org>
> wrote:
>
>> On 05.12.2022 15:15, Andreas Rheinhardt wrote:
>> > Timo Rothenpieler:
>> >> In my tests, this lead to a notable speed increase with the amount
>> >> of threads used. Decoding a 720p sample gave the following results:
>> >>
>> >> 1 Thread: 1428 FPS
>> >> 2 Threads: 2501 FPS
>> >> 8 Threads: 7575 FPS
>> >> Automatic: 11326 FPS (On a 16 Core/32 Threads system)
>> >> ---
>> >>   libavcodec/jpeglsdec.c |  2 +-
>> >>   libavcodec/mjpegdec.c  | 13 +++++++------
>> >>   libavcodec/sp5xdec.c   |  4 ++--
>> >>   3 files changed, 10 insertions(+), 9 deletions(-)
>> >>
>>
>
> I made almost same patch, can you apply this one?
> Thanks.
>

Actually, on better look, this one is more complicated, and does not apply
anymore.
So ignore my 'request'.


>
>
>> >> diff --git a/libavcodec/jpeglsdec.c b/libavcodec/jpeglsdec.c
>> >> index 2e6d018ea6..c0642e8e30 100644
>> >> --- a/libavcodec/jpeglsdec.c
>> >> +++ b/libavcodec/jpeglsdec.c
>> >> @@ -559,7 +559,7 @@ const FFCodec ff_jpegls_decoder = {
>> >>       .init           = ff_mjpeg_decode_init,
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP |
>> >>                         FF_CODEC_CAP_SETS_PKT_DTS,
>> >>   };
>> >> diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
>> >> index 9b7465abe7..d30d722398 100644
>> >> --- a/libavcodec/mjpegdec.c
>> >> +++ b/libavcodec/mjpegdec.c
>> >> @@ -54,6 +54,7 @@
>> >>   #include "exif.h"
>> >>   #include "bytestream.h"
>> >>   #include "tiff_common.h"
>> >> +#include "thread.h"
>> >>
>> >>
>> >>   static int init_default_huffman_tables(MJpegDecodeContext *s)
>> >> @@ -713,7 +714,7 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
>> >>                   s->avctx->pix_fmt,
>> >>                   AV_PIX_FMT_NONE,
>> >>               };
>> >> -            s->hwaccel_pix_fmt = ff_get_format(s->avctx, pix_fmts);
>> >> +            s->hwaccel_pix_fmt = ff_thread_get_format(s->avctx,
>> pix_fmts);
>> >>               if (s->hwaccel_pix_fmt < 0)
>> >>                   return AVERROR(EINVAL);
>> >>
>> >> @@ -729,7 +730,7 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
>> >>           }
>> >>
>> >>           av_frame_unref(s->picture_ptr);
>> >> -        if (ff_get_buffer(s->avctx, s->picture_ptr,
>> AV_GET_BUFFER_FLAG_REF) < 0)
>> >> +        if (ff_thread_get_buffer(s->avctx, s->picture_ptr,
>> AV_GET_BUFFER_FLAG_REF) < 0)
>> >>               return -1;
>> >>           s->picture_ptr->pict_type = AV_PICTURE_TYPE_I;
>> >>           s->picture_ptr->key_frame = 1;
>> >> @@ -2388,7 +2389,7 @@ static int mjpeg_get_packet(AVCodecContext
>> *avctx)
>> >>       int ret;
>> >>
>> >>       av_packet_unref(s->pkt);
>> >> -    ret = ff_decode_get_packet(avctx, s->pkt);
>> >> +    ret = ff_thread_decode_get_packet(avctx, s->pkt);
>> >>       if (ret < 0)
>> >>           return ret;
>> >>
>> >> @@ -3020,7 +3021,7 @@ const FFCodec ff_mjpeg_decoder = {
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >>       .flush          = decode_flush,
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .p.max_lowres   = 3,
>> >>       .p.priv_class   = &mjpegdec_class,
>> >>       .p.profiles     = NULL_IF_CONFIG_SMALL(ff_mjpeg_profiles),
>> >> @@ -3050,7 +3051,7 @@ const FFCodec ff_thp_decoder = {
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >>       .flush          = decode_flush,
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .p.max_lowres   = 3,
>> >>       .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP |
>> >>                         FF_CODEC_CAP_SETS_PKT_DTS,
>> >> @@ -3068,7 +3069,7 @@ const FFCodec ff_smvjpeg_decoder = {
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >>       .flush          = decode_flush,
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .caps_internal  = FF_CODEC_CAP_EXPORTS_CROPPING |
>> >>                         FF_CODEC_CAP_SETS_PKT_DTS |
>> FF_CODEC_CAP_INIT_CLEANUP,
>> >>   };
>> >> diff --git a/libavcodec/sp5xdec.c b/libavcodec/sp5xdec.c
>> >> index 394448c5a9..8b08dc672a 100644
>> >> --- a/libavcodec/sp5xdec.c
>> >> +++ b/libavcodec/sp5xdec.c
>> >> @@ -101,7 +101,7 @@ const FFCodec ff_sp5x_decoder = {
>> >>       .init           = ff_mjpeg_decode_init,
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .p.max_lowres   = 3,
>> >>       .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP |
>> >>                         FF_CODEC_CAP_SETS_PKT_DTS,
>> >> @@ -118,7 +118,7 @@ const FFCodec ff_amv_decoder = {
>> >>       .close          = ff_mjpeg_decode_end,
>> >>       FF_CODEC_RECEIVE_FRAME_CB(ff_mjpeg_receive_frame),
>> >>       .p.max_lowres   = 3,
>> >> -    .p.capabilities = AV_CODEC_CAP_DR1,
>> >> +    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
>> >>       .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP |
>> >>                         FF_CODEC_CAP_SETS_PKT_DTS,
>> >>   };
>> >
>> > Can you test the sample that Michael mentioned here:
>> >
>> https://patchwork.ffmpeg.org/project/ffmpeg/patch/AS8PR01MB7944E105BE990A5D01EF89208FEF9@AS8PR01MB7944.eurprd01.prod.exchangelabs.com/
>> ?
>> > (I never got around to analyzing this, but if I am not mistaken, it
>> > shows that this decoder is not a simple one-in, one-out decoder, so that
>> > making it multithreaded will be more complicated than just adding the
>> > flag and using ff_thread_get_buffer/format.)
>>
>> Assuming this is the right file:
>> https://trac.ffmpeg.org/attachment/ticket/1915/not_interleaved.avi
>>
>> It does not decode for me at all, with or without this patch applied:
>>
>> > [mjpeg @ 0x562e81877c80] No JPEG data found in image
>> > Error while decoding stream #0:0: Invalid data found when processing
>> input
>>
>>
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>


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