[FFmpeg-devel] [PATCH] avcodec: do not use init_static_data on some codecs

[wm4]

On Sat,  3 Feb 2018 01:36:37 +0700
Muhammad Faiz <mfcc64 at gmail.com> wrote:

> They don't modify AVCodec, no needs to call it at register. They will be
> wasteful if these codecs are unused. Instead, call static data initialization
> at codecs' init.
> 
> Benchmark:
> old: 51281340 decicycles in avcodec_register_all,       1 runs,      0 skips
> new:  6738960 decicycles in avcodec_register_all,       1 runs,      0 skips
> 
> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
> ---
>  libavcodec/jpeg2000dec.c | 16 +++++++++-------
>  libavcodec/qdmc.c        |  7 +++++--
>  libavcodec/wmavoice.c    |  7 +++++--
>  3 files changed, 19 insertions(+), 11 deletions(-)
> 
> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> index 01fe4b3949..4cf8a2880c 100644
> --- a/libavcodec/jpeg2000dec.c
> +++ b/libavcodec/jpeg2000dec.c
> @@ -34,6 +34,7 @@
>  #include "libavutil/imgutils.h"
>  #include "libavutil/opt.h"
>  #include "libavutil/pixdesc.h"
> +#include "libavutil/thread.h"
>  #include "avcodec.h"
>  #include "bytestream.h"
>  #include "internal.h"
> @@ -2142,10 +2143,18 @@ static int jp2_find_codestream(Jpeg2000DecoderContext *s)
>      return 0;
>  }
>  
> +static av_cold void jpeg2000_init_static_data(void)
> +{
> +    ff_jpeg2000_init_tier1_luts();
> +    ff_mqc_init_context_tables();
> +}
> +
>  static av_cold int jpeg2000_decode_init(AVCodecContext *avctx)
>  {
> +    static AVOnce init_static_once = AV_ONCE_INIT;
>      Jpeg2000DecoderContext *s = avctx->priv_data;
>  
> +    ff_thread_once(&init_static_once, jpeg2000_init_static_data);
>      ff_jpeg2000dsp_init(&s->dsp);
>  
>      return 0;
> @@ -2223,12 +2232,6 @@ end:
>      return ret;
>  }
>  
> -static av_cold void jpeg2000_init_static_data(AVCodec *codec)
> -{
> -    ff_jpeg2000_init_tier1_luts();
> -    ff_mqc_init_context_tables();
> -}
> -
>  #define OFFSET(x) offsetof(Jpeg2000DecoderContext, x)
>  #define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
>  
> @@ -2252,7 +2255,6 @@ AVCodec ff_jpeg2000_decoder = {
>      .id               = AV_CODEC_ID_JPEG2000,
>      .capabilities     = AV_CODEC_CAP_SLICE_THREADS | AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_DR1,
>      .priv_data_size   = sizeof(Jpeg2000DecoderContext),
> -    .init_static_data = jpeg2000_init_static_data,
>      .init             = jpeg2000_decode_init,
>      .decode           = jpeg2000_decode_frame,
>      .priv_class       = &jpeg2000_class,
> diff --git a/libavcodec/qdmc.c b/libavcodec/qdmc.c
> index 1c8952b97b..f1f86accd8 100644
> --- a/libavcodec/qdmc.c
> +++ b/libavcodec/qdmc.c
> @@ -26,6 +26,7 @@
>  #define BITSTREAM_READER_LE
>  
>  #include "libavutil/channel_layout.h"
> +#include "libavutil/thread.h"
>  
>  #include "avcodec.h"
>  #include "bytestream.h"
> @@ -204,7 +205,7 @@ static const uint8_t phase_diff_codes[] = {
>                             INIT_VLC_LE | INIT_VLC_USE_NEW_STATIC); \
>      } while (0)
>  
> -static av_cold void qdmc_init_static_data(AVCodec *codec)
> +static av_cold void qdmc_init_static_data(void)
>  {
>      int i;
>  
> @@ -250,10 +251,13 @@ static void make_noises(QDMCContext *s)
>  
>  static av_cold int qdmc_decode_init(AVCodecContext *avctx)
>  {
> +    static AVOnce init_static_once = AV_ONCE_INIT;
>      QDMCContext *s = avctx->priv_data;
>      int fft_size, fft_order, size, g, j, x;
>      GetByteContext b;
>  
> +    ff_thread_once(&init_static_once, qdmc_init_static_data);
> +
>      if (!avctx->extradata || (avctx->extradata_size < 48)) {
>          av_log(avctx, AV_LOG_ERROR, "extradata missing or truncated\n");
>          return AVERROR_INVALIDDATA;
> @@ -775,7 +779,6 @@ AVCodec ff_qdmc_decoder = {
>      .id               = AV_CODEC_ID_QDMC,
>      .priv_data_size   = sizeof(QDMCContext),
>      .init             = qdmc_decode_init,
> -    .init_static_data = qdmc_init_static_data,
>      .close            = qdmc_decode_close,
>      .decode           = qdmc_decode_frame,
>      .flush            = qdmc_flush,
> diff --git a/libavcodec/wmavoice.c b/libavcodec/wmavoice.c
> index 3f86d0da35..444e303b0d 100644
> --- a/libavcodec/wmavoice.c
> +++ b/libavcodec/wmavoice.c
> @@ -30,6 +30,7 @@
>  #include "libavutil/channel_layout.h"
>  #include "libavutil/float_dsp.h"
>  #include "libavutil/mem.h"
> +#include "libavutil/thread.h"
>  #include "avcodec.h"
>  #include "internal.h"
>  #include "get_bits.h"
> @@ -310,7 +311,7 @@ static av_cold int decode_vbmtree(GetBitContext *gb, int8_t vbm_tree[25])
>      return 0;
>  }
>  
> -static av_cold void wmavoice_init_static_data(AVCodec *codec)
> +static av_cold void wmavoice_init_static_data(void)
>  {
>      static const uint8_t bits[] = {
>           2,  2,  2,  4,  4,  4,
> @@ -365,9 +366,12 @@ static av_cold void wmavoice_flush(AVCodecContext *ctx)
>   */
>  static av_cold int wmavoice_decode_init(AVCodecContext *ctx)
>  {
> +    static AVOnce init_static_once = AV_ONCE_INIT;
>      int n, flags, pitch_range, lsp16_flag;
>      WMAVoiceContext *s = ctx->priv_data;
>  
> +    ff_thread_once(&init_static_once, wmavoice_init_static_data);
> +
>      /**
>       * Extradata layout:
>       * - byte  0-18: WMAPro-in-WMAVoice extradata (see wmaprodec.c),
> @@ -1991,7 +1995,6 @@ AVCodec ff_wmavoice_decoder = {
>      .id               = AV_CODEC_ID_WMAVOICE,
>      .priv_data_size   = sizeof(WMAVoiceContext),
>      .init             = wmavoice_decode_init,
> -    .init_static_data = wmavoice_init_static_data,
>      .close            = wmavoice_decode_end,
>      .decode           = wmavoice_decode_packet,
>      .capabilities     = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,

+1, probably slightly better than before.