[FFmpeg-devel] [WIP][RFC][PATCH] avfilter: add zscale filter

Paul B Mahol onemda at gmail.com
Mon Sep 21 21:22:25 CEST 2015


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 configure                |   4 +
 libavfilter/Makefile     |   1 +
 libavfilter/allfilters.c |   1 +
 libavfilter/vf_zscale.c  | 546 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 552 insertions(+)
 create mode 100644 libavfilter/vf_zscale.c

diff --git a/configure b/configure
index d2a25bb..fffa934 100755
--- a/configure
+++ b/configure
@@ -269,6 +269,7 @@ External library support:
   --enable-libxcb-shape    enable X11 grabbing shape rendering [autodetect]
   --enable-libxvid         enable Xvid encoding via xvidcore,
                            native MPEG-4/Xvid encoder exists [no]
+  --enable-libzimg         enable zimg, needed for zscale filter [no]
   --enable-libzmq          enable message passing via libzmq [no]
   --enable-libzvbi         enable teletext support via libzvbi [no]
   --disable-lzma           disable lzma [autodetect]
@@ -1435,6 +1436,7 @@ EXTERNAL_LIBRARY_LIST="
     libxcb_shape
     libxcb_xfixes
     libxvid
+    libzimg
     libzmq
     libzvbi
     lzma
@@ -2817,6 +2819,7 @@ tinterlace_pad_test_deps="tinterlace_filter"
 uspp_filter_deps="gpl avcodec"
 zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
+zscale_filter_deps="libzimg"
 
 # examples
 avio_reading="avformat avcodec avutil"
@@ -5341,6 +5344,7 @@ enabled libx265           && require_pkg_config x265 x265.h x265_api_get &&
                                die "ERROR: libx265 version must be >= 57."; }
 enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
 enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
+enabled libzimg           && require_pkg_config zimg zimg3.h zimg2_get_api_version
 enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
 enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new -lzvbi
 enabled mmal              && { check_lib interface/mmal/mmal.h mmal_port_connect -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host ||
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 4bbe972..ccc2f02 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -240,6 +240,7 @@ OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += vf_yadif.o
 OBJS-$(CONFIG_ZMQ_FILTER)                    += f_zmq.o
 OBJS-$(CONFIG_ZOOMPAN_FILTER)                += vf_zoompan.o
+OBJS-$(CONFIG_ZSCALE_FILTER)                 += vf_zscale.o
 
 OBJS-$(CONFIG_ALLRGB_FILTER)                 += vsrc_testsrc.o
 OBJS-$(CONFIG_ALLYUV_FILTER)                 += vsrc_testsrc.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 3b3a49f..56696f8 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -261,6 +261,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(YADIF,          yadif,          vf);
     REGISTER_FILTER(ZMQ,            zmq,            vf);
     REGISTER_FILTER(ZOOMPAN,        zoompan,        vf);
+    REGISTER_FILTER(ZSCALE,         zscale,         vf);
 
     REGISTER_FILTER(ALLRGB,         allrgb,         vsrc);
     REGISTER_FILTER(ALLYUV,         allyuv,         vsrc);
diff --git a/libavfilter/vf_zscale.c b/libavfilter/vf_zscale.c
new file mode 100644
index 0000000..74bdb49
--- /dev/null
+++ b/libavfilter/vf_zscale.c
@@ -0,0 +1,546 @@
+/*
+ * Copyright (c) 2015 Paul B Mahol
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * zscale video filter using zimg library
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <zimg3.h>
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+#include "libavutil/avstring.h"
+#include "libavutil/eval.h"
+#include "libavutil/internal.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/avassert.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
+};
+
+typedef struct ZScaleContext {
+    const AVClass *class;
+
+    /**
+     * New dimensions. Special values are:
+     *   0 = original width/height
+     *  -1 = keep original aspect
+     *  -N = try to keep aspect but make sure it is divisible by N
+     */
+    int w, h;
+    int dither;
+    int filter;
+    char *size_str;
+
+    char *w_expr;               ///< width  expression string
+    char *h_expr;               ///< height expression string
+
+    int in_range;
+    int out_range;
+
+    int out_h_chr_pos;
+    int out_v_chr_pos;
+    int in_h_chr_pos;
+    int in_v_chr_pos;
+
+    int force_original_aspect_ratio;
+} ZScaleContext;
+
+static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
+{
+    ZScaleContext *s = ctx->priv;
+    int ret;
+
+    if (s->size_str && (s->w_expr || s->h_expr)) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Size and width/height expressions cannot be set at the same time.\n");
+            return AVERROR(EINVAL);
+    }
+
+    if (s->w_expr && !s->h_expr)
+        FFSWAP(char *, s->w_expr, s->size_str);
+
+    if (s->size_str) {
+        char buf[32];
+        if ((ret = av_parse_video_size(&s->w, &s->h, s->size_str)) < 0) {
+            av_log(ctx, AV_LOG_ERROR,
+                   "Invalid size '%s'\n", s->size_str);
+            return ret;
+        }
+        snprintf(buf, sizeof(buf)-1, "%d", s->w);
+        av_opt_set(s, "w", buf, 0);
+        snprintf(buf, sizeof(buf)-1, "%d", s->h);
+        av_opt_set(s, "h", buf, 0);
+    }
+    if (!s->w_expr)
+        av_opt_set(s, "w", "iw", 0);
+    if (!s->h_expr)
+        av_opt_set(s, "h", "ih", 0);
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pixel_fmts[] = {
+        AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
+        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
+        AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
+        AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
+        AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
+        AV_PIX_FMT_YUVJ411P,
+        AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
+        AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
+        AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
+        AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
+        AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
+        AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_formats_ref(ff_make_format_list(pixel_fmts), &ctx->inputs[0]->out_formats);
+    ff_formats_ref(ff_make_format_list(pixel_fmts), &ctx->outputs[0]->in_formats);
+
+    return 0;
+}
+
+static int config_props(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *inlink = outlink->src->inputs[0];
+    ZScaleContext *s = 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;
+    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 = 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)
+        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;
+
+    /* 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)
+        s->w = s->h = 0;
+
+    if (!(w = s->w))
+        w = inlink->w;
+    if (!(h = s->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;
+
+    /* Note that force_original_aspect_ratio may overwrite the previous set
+     * dimensions so that it is not divisible by the set factors anymore. */
+    if (s->force_original_aspect_ratio) {
+        int tmp_w = av_rescale(h, inlink->w, inlink->h);
+        int tmp_h = av_rescale(w, inlink->h, inlink->w);
+
+        if (s->force_original_aspect_ratio == 1) {
+             w = FFMIN(tmp_w, w);
+             h = FFMIN(tmp_h, h);
+        } else {
+             w = FFMAX(tmp_w, w);
+             h = FFMAX(tmp_h, h);
+        }
+    }
+
+    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");
+
+    outlink->w = w;
+    outlink->h = h;
+
+    if (inlink->w == outlink->w &&
+        inlink->h == outlink->h &&
+        s->in_range == s->out_range &&
+        inlink->format == outlink->format)
+        ;
+    else {
+    }
+
+    if (inlink->sample_aspect_ratio.num){
+        outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
+    } else
+        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+
+    av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d fmt:%s sar:%d/%d\n",
+           inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
+           inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
+           outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
+           outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den);
+    return 0;
+
+fail:
+    av_log(ctx, 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, s->w_expr, s->h_expr);
+    return ret;
+}
+
+static int print_zimg_error(AVFilterContext *ctx)
+{
+    char err_msg[1024];
+    int err_code = zimg_get_last_error(err_msg, sizeof(err_msg));
+
+    av_log(ctx, AV_LOG_ERROR, "code %d: %s\n", err_code, err_msg);
+
+    return err_code;
+}
+
+static int convert_trc(enum AVColorTransferCharacteristic color_trc)
+{
+    switch (color_trc) {
+    case AVCOL_TRC_UNSPECIFIED:
+        return ZIMG_TRANSFER_UNSPECIFIED;
+    case AVCOL_TRC_BT709:
+        return ZIMG_TRANSFER_709;
+    case AVCOL_TRC_SMPTE170M:
+        return ZIMG_TRANSFER_601;
+    case AVCOL_TRC_LINEAR:
+        return ZIMG_TRANSFER_LINEAR;
+    case AVCOL_TRC_BT2020_10:
+        return ZIMG_TRANSFER_2020_10;
+    case AVCOL_TRC_BT2020_12:
+        return ZIMG_TRANSFER_2020_12;
+    }
+    return ZIMG_TRANSFER_UNSPECIFIED;
+}
+
+static int convert_primaries(enum AVColorPrimaries color_primaries)
+{
+    switch (color_primaries) {
+    case AVCOL_PRI_UNSPECIFIED:
+        return ZIMG_PRIMARIES_UNSPECIFIED;
+    case AVCOL_PRI_BT709:
+        return ZIMG_PRIMARIES_709;
+    case AVCOL_PRI_SMPTE170M:
+        return ZIMG_PRIMARIES_170M;
+    case AVCOL_PRI_SMPTE240M:
+        return ZIMG_PRIMARIES_240M;
+    case AVCOL_PRI_BT2020:
+        return ZIMG_PRIMARIES_2020;
+    }
+    return ZIMG_PRIMARIES_UNSPECIFIED;
+}
+
+static int filter_frame(AVFilterLink *link, AVFrame *in)
+{
+    ZScaleContext *s = link->dst->priv;
+    AVFilterLink *outlink = link->dst->outputs[0];
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
+    const AVPixFmtDescriptor *odesc = av_pix_fmt_desc_get(outlink->format);
+    zimg_image_buffer_const src_buf = { ZIMG_API_VERSION };
+    zimg_image_buffer dst_buf = { { ZIMG_API_VERSION } };
+    zimg_image_format src_format, dst_format;
+    zimg_filter_graph_params params;
+    zimg_filter_graph *graph;
+    char buf[32];
+    size_t tmp_size;
+    int in_range, ret = 0, plane;
+    AVFrame *out;
+    void *tmp = NULL;
+
+    if (av_frame_get_colorspace(in) == AVCOL_SPC_YCGCO)
+        av_log(link->dst, AV_LOG_WARNING, "Detected unsupported YCgCo colorspace.\n");
+
+    if(   in->width  != link->w
+       || in->height != link->h
+       || in->format != link->format) {
+        snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
+        av_opt_set(s, "w", buf, 0);
+        snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
+        av_opt_set(s, "h", buf, 0);
+
+        link->dst->inputs[0]->format = in->format;
+        link->dst->inputs[0]->w      = in->width;
+        link->dst->inputs[0]->h      = in->height;
+
+        if ((ret = config_props(outlink)) < 0)
+            return ret;
+    }
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+
+    av_frame_copy_props(out, in);
+    out->width  = outlink->w;
+    out->height = outlink->h;
+
+    in_range = av_frame_get_color_range(in);
+
+    av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
+              (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
+              (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
+              INT_MAX);
+
+    zimg2_image_format_default(&src_format, ZIMG_API_VERSION);
+    zimg2_image_format_default(&dst_format, ZIMG_API_VERSION);
+    zimg2_filter_graph_params_default(&params, ZIMG_API_VERSION);
+
+    params.dither_type = s->dither;
+    params.cpu_type = ZIMG_CPU_AUTO;
+    params.resample_filter = s->filter;
+    params.resample_filter_uv = s->filter;
+
+    src_format.width = in->width;
+    src_format.height = in->height;
+    src_format.subsample_w = desc->log2_chroma_w;
+    src_format.subsample_h = desc->log2_chroma_h;
+    src_format.depth = desc->comp[0].depth;
+    src_format.pixel_type = desc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;
+    src_format.color_family = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_COLOR_RGB : ZIMG_COLOR_YUV;
+    src_format.matrix_coefficients = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_MATRIX_RGB : ZIMG_MATRIX_UNSPECIFIED;
+    src_format.transfer_characteristics = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_TRANSFER_UNSPECIFIED : convert_trc(in->color_trc);
+    src_format.color_primaries = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_PRIMARIES_UNSPECIFIED : convert_primaries(in->color_primaries);
+
+    dst_format.width = out->width;
+    dst_format.height = out->height;
+    dst_format.subsample_w = odesc->log2_chroma_w;
+    dst_format.subsample_h = odesc->log2_chroma_h;
+    dst_format.depth = odesc->comp[0].depth;
+    dst_format.pixel_type = dst_format.depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;
+    dst_format.color_family = (odesc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_COLOR_RGB : ZIMG_COLOR_YUV;
+    dst_format.matrix_coefficients = (odesc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_MATRIX_RGB : ZIMG_MATRIX_UNSPECIFIED;
+    dst_format.transfer_characteristics = (odesc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_TRANSFER_UNSPECIFIED : convert_trc(out->color_trc);
+    dst_format.color_primaries = (odesc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_PRIMARIES_UNSPECIFIED : convert_primaries(out->color_primaries);
+
+    graph = zimg2_filter_graph_build(&src_format, &dst_format, &params);
+    if (!graph) {
+        ret = print_zimg_error(link->dst);
+        goto fail;
+    }
+
+    if ((ret = zimg2_filter_graph_get_tmp_size(graph, &tmp_size))) {
+        ret = print_zimg_error(link->dst);
+        goto fail;
+    }
+
+    tmp = av_malloc(tmp_size);
+    if (!tmp) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    for (plane = 0; plane < 3; plane++) {
+        int p = desc->comp[plane].plane;
+        src_buf.data[plane] = in->data[p];
+        src_buf.stride[plane] = in->linesize[p];
+        src_buf.mask[plane] = -1;
+
+        p = odesc->comp[plane].plane;
+        dst_buf.m.data[plane] = out->data[p];
+        dst_buf.m.stride[plane] = out->linesize[p];
+        dst_buf.m.mask[plane] = -1;
+    }
+
+    ret = zimg2_filter_graph_process(graph, &src_buf, &dst_buf, tmp, 0, 0, 0, 0);
+    if (ret) {
+        print_zimg_error(link->dst);
+        goto fail;
+    }
+fail:
+    av_frame_free(&in);
+    zimg2_filter_graph_free(graph);
+    av_freep(&tmp);
+    if (ret)
+        return ret;
+    return ff_filter_frame(outlink, out);
+}
+
+static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
+                           char *res, int res_len, int flags)
+{
+    ZScaleContext *s = ctx->priv;
+    int ret;
+
+    if (   !strcmp(cmd, "width")  || !strcmp(cmd, "w")
+        || !strcmp(cmd, "height") || !strcmp(cmd, "h")) {
+
+        int old_w = s->w;
+        int old_h = s->h;
+        AVFilterLink *outlink = ctx->outputs[0];
+
+        av_opt_set(s, cmd, args, 0);
+        if ((ret = config_props(outlink)) < 0) {
+            s->w = old_w;
+            s->h = old_h;
+        }
+    } else
+        ret = AVERROR(ENOSYS);
+
+    return ret;
+}
+
+#define OFFSET(x) offsetof(ZScaleContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption zscale_options[] = {
+    { "w",      "Output video width",  OFFSET(w_expr),    AV_OPT_TYPE_STRING,        .flags = FLAGS },
+    { "width",  "Output video width",  OFFSET(w_expr),    AV_OPT_TYPE_STRING,        .flags = FLAGS },
+    { "h",      "Output video height", OFFSET(h_expr),    AV_OPT_TYPE_STRING,        .flags = FLAGS },
+    { "height", "Output video height", OFFSET(h_expr),    AV_OPT_TYPE_STRING,        .flags = FLAGS },
+    { "size",   "set video size",      OFFSET(size_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
+    { "s",      "set video size",      OFFSET(size_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
+    { "dither", "set dither type",     OFFSET(dither),    AV_OPT_TYPE_INT, {.i64 = 0}, 0, ZIMG_DITHER_ERROR_DIFFUSION, FLAGS, "dither" },
+    { "d",      "set dither type",     OFFSET(dither),    AV_OPT_TYPE_INT, {.i64 = 0}, 0, ZIMG_DITHER_ERROR_DIFFUSION, FLAGS, "dither" },
+    { "none",            0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_NONE}, 0, 0, FLAGS, "dither" },
+    { "ordered",         0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_ORDERED}, 0, 0, FLAGS, "dither" },
+    { "random",          0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_RANDOM}, 0, 0, FLAGS, "dither" },
+    { "error_diffusion", 0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_DITHER_ERROR_DIFFUSION}, 0, 0, FLAGS, "dither" },
+    { "filter", "set filter type",     OFFSET(filter),    AV_OPT_TYPE_INT, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, ZIMG_RESIZE_LANCZOS, FLAGS, "filter" },
+    { "f",      "set filter type",     OFFSET(filter),    AV_OPT_TYPE_INT, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, ZIMG_RESIZE_LANCZOS, FLAGS, "filter" },
+    { "point",            0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_POINT}, 0, 0, FLAGS, "filter" },
+    { "bilinear",         0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_BILINEAR}, 0, 0, FLAGS, "filter" },
+    { "bicubic",          0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_BICUBIC},  0, 0, FLAGS, "filter" },
+    { "spline16",         0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_SPLINE16}, 0, 0, FLAGS, "filter" },
+    { "splite36",         0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_SPLINE36}, 0, 0, FLAGS, "filter" },
+    { "lanczos",          0,            0,                 AV_OPT_TYPE_CONST, {.i64 = ZIMG_RESIZE_LANCZOS},  0, 0, FLAGS, "filter" },
+    { NULL }
+};
+
+static const AVClass zscale_class = {
+    .class_name       = "zscale",
+    .item_name        = av_default_item_name,
+    .option           = zscale_options,
+    .version          = LIBAVUTIL_VERSION_INT,
+    .category         = AV_CLASS_CATEGORY_FILTER,
+};
+
+static const AVFilterPad avfilter_vf_zscale_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad avfilter_vf_zscale_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_props,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_zscale = {
+    .name            = "zscale",
+    .description     = NULL_IF_CONFIG_SMALL("Apply resizing, colorspace and bit depth conversion."),
+    .init_dict       = init_dict,
+    .query_formats   = query_formats,
+    .priv_size       = sizeof(ZScaleContext),
+    .priv_class      = &zscale_class,
+    .inputs          = avfilter_vf_zscale_inputs,
+    .outputs         = avfilter_vf_zscale_outputs,
+    .process_command = process_command,
+};
-- 
1.9.1



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