[FFmpeg-devel] [PATCH] avfilter/scale: refactor common code for scaling height/width expressions
Mark Thompson
sw at jkqxz.net
Thu Feb 2 00:40:33 EET 2017
On 01/02/17 00:46, Aman Gupta wrote:
> From: Aman Gupta <aman at tmm1.net>
>
> Implements support for height/width expressions in vf_scale_vaapi,
> by refactoring common code into a new libavfilter/scale.c
Nice! Patch as a whole LGTM, some minor nits below.
> ---
> libavfilter/Makefile | 8 +--
> libavfilter/scale.c | 143 +++++++++++++++++++++++++++++++++++++++++++
> libavfilter/scale.h | 31 ++++++++++
> libavfilter/vf_scale.c | 109 +++------------------------------
> libavfilter/vf_scale_npp.c | 87 +++-----------------------
> libavfilter/vf_scale_vaapi.c | 18 +++++-
> 6 files changed, 208 insertions(+), 188 deletions(-)
> create mode 100644 libavfilter/scale.c
> create mode 100644 libavfilter/scale.h
>
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 68a94be..3231f08 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -257,10 +257,10 @@ OBJS-$(CONFIG_REPEATFIELDS_FILTER) += vf_repeatfields.o
> OBJS-$(CONFIG_REVERSE_FILTER) += f_reverse.o
> OBJS-$(CONFIG_ROTATE_FILTER) += vf_rotate.o
> OBJS-$(CONFIG_SAB_FILTER) += vf_sab.o
> -OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o
> -OBJS-$(CONFIG_SCALE_NPP_FILTER) += vf_scale_npp.o
> -OBJS-$(CONFIG_SCALE_VAAPI_FILTER) += vf_scale_vaapi.o
> -OBJS-$(CONFIG_SCALE2REF_FILTER) += vf_scale.o
> +OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o scale.o
> +OBJS-$(CONFIG_SCALE_NPP_FILTER) += vf_scale_npp.o scale.o
> +OBJS-$(CONFIG_SCALE_VAAPI_FILTER) += vf_scale_vaapi.o scale.o
> +OBJS-$(CONFIG_SCALE2REF_FILTER) += vf_scale.o scale.o
> OBJS-$(CONFIG_SELECT_FILTER) += f_select.o
> OBJS-$(CONFIG_SELECTIVECOLOR_FILTER) += vf_selectivecolor.o
> OBJS-$(CONFIG_SENDCMD_FILTER) += f_sendcmd.o
> diff --git a/libavfilter/scale.c b/libavfilter/scale.c
> new file mode 100644
> index 0000000..b0f4be2
> --- /dev/null
> +++ b/libavfilter/scale.c
> @@ -0,0 +1,143 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "scale.h"
> +
> +static const char *const var_names[] = {
> + "PI",
> + "PHI",
> + "E",
> + "in_w", "iw",
> + "in_h", "ih",
> + "out_w", "ow",
> + "out_h", "oh",
> + "a",
> + "sar",
> + "dar",
> + "hsub",
> + "vsub",
> + "ohsub",
> + "ovsub",
> + NULL
> +};
> +
> +enum var_name {
> + VAR_PI,
> + VAR_PHI,
> + VAR_E,
> + VAR_IN_W, VAR_IW,
> + VAR_IN_H, VAR_IH,
> + VAR_OUT_W, VAR_OW,
> + VAR_OUT_H, VAR_OH,
> + VAR_A,
> + VAR_SAR,
> + VAR_DAR,
> + VAR_HSUB,
> + VAR_VSUB,
> + VAR_OHSUB,
> + VAR_OVSUB,
> + VARS_NB
> +};
> +
> +int ff_scale_eval_dimensions(void *ctx,
> + const char *w_expr, const char *h_expr,
> + AVFilterLink *inlink, AVFilterLink *outlink,
> + int *ret_w, int *ret_h)
> +{
> + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> + const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
> + const char *expr;
> + int w, h;
> + int factor_w, factor_h;
> + int eval_w, eval_h;
> + int ret;
> + double var_values[VARS_NB], res;
> +
> + var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
> + var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
> + var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
> + var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
> + var_values[VAR_A] = (double) inlink->w / inlink->h;
> + var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
> + (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
> + var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
> + var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
> + var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
> + var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
> + var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
> +
> + /* evaluate width and height */
> + av_expr_parse_and_eval(&res, (expr = w_expr),
> + var_names, var_values,
> + NULL, NULL, NULL, NULL, NULL, 0, ctx);
> + eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
> +
> + if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr),
> + var_names, var_values,
> + NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> + goto fail;
> + eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
> + /* evaluate again the width, as it may depend on the output height */
> + if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr),
> + var_names, var_values,
> + NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> + goto fail;
> + eval_w = res;
> +
> + w = eval_w;
> + h = eval_h;
> +
> + /* Check if it is requested that the result has to be divisible by a some
> + * factor (w or h = -n with n being the factor). */
> + factor_w = 1;
> + factor_h = 1;
> + if (w < -1) {
> + factor_w = -w;
> + }
> + if (h < -1) {
> + factor_h = -h;
> + }
> +
> + if (w < 0 && h < 0)
> + eval_w = eval_h = 0;
> +
> + if (!(w = eval_w))
> + w = inlink->w;
> + if (!(h = eval_h))
> + h = inlink->h;
> +
> + /* Make sure that the result is divisible by the factor we determined
> + * earlier. If no factor was set, it is nothing will happen as the default
> + * factor is 1 */
> + if (w < 0)
> + w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w;
> + if (h < 0)
> + h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h;
> +
> + *ret_w = w;
> + *ret_h = h;
> +
> + return 0;
> +
> +fail:
> + av_log(NULL, AV_LOG_ERROR,
> + "Error when evaluating the expression '%s'.\n"
> + "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
> + expr, w_expr, h_expr);
> + return ret;
> +}
> diff --git a/libavfilter/scale.h b/libavfilter/scale.h
> new file mode 100644
> index 0000000..c95515d
> --- /dev/null
> +++ b/libavfilter/scale.h
> @@ -0,0 +1,31 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#ifndef AVFILTER_SCALE_H
> +#define AVFILTER_SCALE_H
> +
> +#include <stdint.h>
> +#include "avfilter.h"
> +#include "libavutil/eval.h"
> +#include "libavutil/pixdesc.h"
You don't need all of these includes in the header; they should go in scale.c.
> +
> +int ff_scale_eval_dimensions(void *ctx,
> + const char *w_expr, const char *h_expr,
> + AVFilterLink *inlink, AVFilterLink *outlink,
> + int *ret_w, int *ret_h);
> +#endif
> diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
> index 22bee96..8645da7 100644
> --- a/libavfilter/vf_scale.c
> +++ b/libavfilter/vf_scale.c
> @@ -29,9 +29,9 @@
> #include "avfilter.h"
> #include "formats.h"
> #include "internal.h"
> +#include "scale.h"
> #include "video.h"
> #include "libavutil/avstring.h"
> -#include "libavutil/eval.h"
> #include "libavutil/internal.h"
> #include "libavutil/mathematics.h"
> #include "libavutil/opt.h"
> @@ -41,43 +41,12 @@
> #include "libavutil/avassert.h"
> #include "libswscale/swscale.h"
>
> -static const char *const var_names[] = {
> - "in_w", "iw",
> - "in_h", "ih",
> - "out_w", "ow",
> - "out_h", "oh",
> - "a",
> - "sar",
> - "dar",
> - "hsub",
> - "vsub",
> - "ohsub",
> - "ovsub",
> - NULL
> -};
> -
> -enum var_name {
> - VAR_IN_W, VAR_IW,
> - VAR_IN_H, VAR_IH,
> - VAR_OUT_W, VAR_OW,
> - VAR_OUT_H, VAR_OH,
> - VAR_A,
> - VAR_SAR,
> - VAR_DAR,
> - VAR_HSUB,
> - VAR_VSUB,
> - VAR_OHSUB,
> - VAR_OVSUB,
> - VARS_NB
> -};
> -
> enum EvalMode {
> EVAL_MODE_INIT,
> EVAL_MODE_FRAME,
> EVAL_MODE_NB
> };
>
> -
> typedef struct ScaleContext {
> const AVClass *class;
> struct SwsContext *sws; ///< software scaler context
> @@ -256,74 +225,16 @@ static int config_props(AVFilterLink *outlink)
> outlink->src->inputs[1] :
> outlink->src->inputs[0];
> enum AVPixelFormat outfmt = outlink->format;
> - ScaleContext *scale = ctx->priv;
> const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> - const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
> - int64_t w, h;
> - double var_values[VARS_NB], res;
> - char *expr;
> + ScaleContext *scale = ctx->priv;
> + int w, h;
> int ret;
> - int factor_w, factor_h;
> -
> - var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
> - var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
> - var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
> - var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
> - var_values[VAR_A] = (double) inlink->w / inlink->h;
> - var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
> - (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
> - var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
> - var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
> - var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
> - var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
> - var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
> -
> - /* evaluate width and height */
> - av_expr_parse_and_eval(&res, (expr = scale->w_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx);
> - scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
> - if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> - goto fail;
> - scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
> - /* evaluate again the width, as it may depend on the output height */
> - if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> - goto fail;
> - scale->w = res;
> -
> - w = scale->w;
> - h = scale->h;
> -
> - /* Check if it is requested that the result has to be divisible by a some
> - * factor (w or h = -n with n being the factor). */
> - factor_w = 1;
> - factor_h = 1;
> - if (w < -1) {
> - factor_w = -w;
> - }
> - if (h < -1) {
> - factor_h = -h;
> - }
> -
> - if (w < 0 && h < 0)
> - scale->w = scale->h = 0;
>
> - if (!(w = scale->w))
> - w = inlink->w;
> - if (!(h = scale->h))
> - h = inlink->h;
> -
> - /* Make sure that the result is divisible by the factor we determined
> - * earlier. If no factor was set, it is nothing will happen as the default
> - * factor is 1 */
> - if (w < 0)
> - w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w;
> - if (h < 0)
> - h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h;
> + if ((ret = ff_scale_eval_dimensions(ctx,
> + scale->w_expr, scale->h_expr,
> + inlink, outlink,
> + &w, &h)) < 0)
> + goto fail;
>
> /* Note that force_original_aspect_ratio may overwrite the previous set
> * dimensions so that it is not divisible by the set factors anymore. */
> @@ -439,10 +350,6 @@ static int config_props(AVFilterLink *outlink)
> return 0;
>
> fail:
> - av_log(NULL, AV_LOG_ERROR,
> - "Error when evaluating the expression '%s'.\n"
> - "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
> - expr, scale->w_expr, scale->h_expr);
> return ret;
> }
>
> diff --git a/libavfilter/vf_scale_npp.c b/libavfilter/vf_scale_npp.c
> index 1abfdd1..84d88eb 100644
> --- a/libavfilter/vf_scale_npp.c
> +++ b/libavfilter/vf_scale_npp.c
> @@ -27,7 +27,6 @@
>
> #include "libavutil/avstring.h"
> #include "libavutil/common.h"
> -#include "libavutil/eval.h"
> #include "libavutil/hwcontext.h"
> #include "libavutil/hwcontext_cuda_internal.h"
> #include "libavutil/internal.h"
> @@ -38,6 +37,7 @@
> #include "avfilter.h"
> #include "formats.h"
> #include "internal.h"
> +#include "scale.h"
> #include "video.h"
>
> static const enum AVPixelFormat supported_formats[] = {
> @@ -50,32 +50,6 @@ static const enum AVPixelFormat deinterleaved_formats[][2] = {
> { AV_PIX_FMT_NV12, AV_PIX_FMT_YUV420P },
> };
>
> -static const char *const var_names[] = {
> - "PI",
> - "PHI",
> - "E",
> - "in_w", "iw",
> - "in_h", "ih",
> - "out_w", "ow",
> - "out_h", "oh",
> - "a", "dar",
> - "sar",
> - NULL
> -};
> -
> -enum var_name {
> - VAR_PI,
> - VAR_PHI,
> - VAR_E,
> - VAR_IN_W, VAR_IW,
> - VAR_IN_H, VAR_IH,
> - VAR_OUT_W, VAR_OW,
> - VAR_OUT_H, VAR_OH,
> - VAR_A, VAR_DAR,
> - VAR_SAR,
> - VARS_NB
> -};
> -
> enum ScaleStage {
> STAGE_DEINTERLEAVE,
> STAGE_RESIZE,
> @@ -359,60 +333,15 @@ static int nppscale_config_props(AVFilterLink *outlink)
> {
> AVFilterContext *ctx = outlink->src;
> AVFilterLink *inlink = outlink->src->inputs[0];
> - NPPScaleContext *s = ctx->priv;
> - int64_t w, h;
> - double var_values[VARS_NB], res;
> - char *expr;
> + NPPScaleContext *s = ctx->priv;
> + int w, h;
> int ret;
>
> - var_values[VAR_PI] = M_PI;
> - var_values[VAR_PHI] = M_PHI;
> - var_values[VAR_E] = M_E;
> - var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
> - var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
> - var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
> - var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
> - var_values[VAR_A] = (double) inlink->w / inlink->h;
> - var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
> - (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
> - var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
> -
> - /* evaluate width and height */
> - av_expr_parse_and_eval(&res, (expr = s->w_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx);
> - s->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
> - if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> + if ((ret = ff_scale_eval_dimensions(s,
> + s->w_expr, s->h_expr,
> + inlink, outlink,
> + &w, &h)) < 0)
> goto fail;
> - s->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
> - /* evaluate again the width, as it may depend on the output height */
> - if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
> - var_names, var_values,
> - NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
> - goto fail;
> - s->w = res;
> -
> - w = s->w;
> - h = s->h;
> -
> - /* sanity check params */
> - if (w < -1 || h < -1) {
> - av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
> - return AVERROR(EINVAL);
> - }
> - if (w == -1 && h == -1)
> - s->w = s->h = 0;
> -
> - if (!(w = s->w))
> - w = inlink->w;
> - if (!(h = s->h))
> - h = inlink->h;
> - if (w == -1)
> - w = av_rescale(h, inlink->w, inlink->h);
> - if (h == -1)
> - h = av_rescale(w, inlink->h, inlink->w);
>
> if (w > INT_MAX || h > INT_MAX ||
> (h * inlink->w) > INT_MAX ||
> (w * inlink->h) > INT_MAX)
> av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
This test doesn't work any more - all of w, h and the corresponding AVFilterLink fields are int, so the test will just invoke undefined behaviour on signed overflow rather than testing anything.
Add some casts, I think? (I assume this is trying to enforce some constraint of the npp API.)
> @@ -439,8 +368,6 @@ static int nppscale_config_props(AVFilterLink *outlink)
> return 0;
>
> fail:
> - av_log(NULL, AV_LOG_ERROR,
> - "Error when evaluating the expression '%s'\n", expr);
> return ret;
> }
>
> diff --git a/libavfilter/vf_scale_vaapi.c b/libavfilter/vf_scale_vaapi.c
> index d1cb246..1abb42e 100644
> --- a/libavfilter/vf_scale_vaapi.c
> +++ b/libavfilter/vf_scale_vaapi.c
> @@ -31,6 +31,7 @@
> #include "avfilter.h"
> #include "formats.h"
> #include "internal.h"
> +#include "scale.h"
>
> typedef struct ScaleVAAPIContext {
> const AVClass *class;
> @@ -50,9 +51,13 @@ typedef struct ScaleVAAPIContext {
>
> char *output_format_string;
> enum AVPixelFormat output_format;
> +
> + char *w_expr; ///< width expression string
> + char *h_expr; ///< height expression string
> +
> + /* computed width/height */
Keep the comment style consistent? (I'd go for // and no doxygen markers, but anything consistent is fine.)
> int output_width;
> int output_height;
> -
> } ScaleVAAPIContext;
>
>
> @@ -110,6 +115,7 @@ static int scale_vaapi_config_input(AVFilterLink *inlink)
>
> static int scale_vaapi_config_output(AVFilterLink *outlink)
> {
> + AVFilterLink *inlink = outlink->src->inputs[0];
> AVFilterContext *avctx = outlink->src;
> ScaleVAAPIContext *ctx = avctx->priv;
> AVVAAPIHWConfig *hwconfig = NULL;
> @@ -162,6 +168,12 @@ static int scale_vaapi_config_output(AVFilterLink *outlink)
> }
> }
>
> + if ((err = ff_scale_eval_dimensions(ctx,
> + ctx->w_expr, ctx->h_expr,
> + inlink, outlink,
> + &ctx->output_width, &ctx->output_height)) < 0)
> + goto fail;
> +
> if (ctx->output_width < constraints->min_width ||
> ctx->output_height < constraints->min_height ||
> ctx->output_width > constraints->max_width ||
> @@ -414,9 +426,9 @@ static av_cold void scale_vaapi_uninit(AVFilterContext *avctx)
> #define FLAGS (AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM)
> static const AVOption scale_vaapi_options[] = {
> { "w", "Output video width",
> - OFFSET(output_width), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, .flags = FLAGS },
> + OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, .flags = FLAGS },
> { "h", "Output video height",
> - OFFSET(output_height), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, .flags = FLAGS },
> + OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, .flags = FLAGS },
> { "format", "Output video format (software format of hardware frames)",
> OFFSET(output_format_string), AV_OPT_TYPE_STRING, .flags = FLAGS },
> { NULL },
>
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