vsrc_buffer: when no frame is available, return an error instead of segfaulting.
[ffmpeg.git] / libavfilter / vf_pixdesctest.c
1 /*
2  * Copyright (c) 2009 Stefano Sabatini
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20
21 /**
22  * @file
23  * pixdesc test filter
24  */
25
26 #include "libavutil/pixdesc.h"
27 #include "avfilter.h"
28
29 typedef struct {
30     const AVPixFmtDescriptor *pix_desc;
31     uint16_t *line;
32 } PixdescTestContext;
33
34 static av_cold void uninit(AVFilterContext *ctx)
35 {
36     PixdescTestContext *priv = ctx->priv;
37     av_freep(&priv->line);
38 }
39
40 static int config_props(AVFilterLink *inlink)
41 {
42     PixdescTestContext *priv = inlink->dst->priv;
43
44     priv->pix_desc = &av_pix_fmt_descriptors[inlink->format];
45
46     if (!(priv->line = av_malloc(sizeof(*priv->line) * inlink->w)))
47         return AVERROR(ENOMEM);
48
49     return 0;
50 }
51
52 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
53 {
54     PixdescTestContext *priv = inlink->dst->priv;
55     AVFilterLink *outlink    = inlink->dst->outputs[0];
56     AVFilterBufferRef *outpicref;
57     int i;
58
59     outlink->out_buf = avfilter_get_video_buffer(outlink, AV_PERM_WRITE,
60                                                 outlink->w, outlink->h);
61     outpicref = outlink->out_buf;
62     avfilter_copy_buffer_ref_props(outpicref, picref);
63
64     for (i = 0; i < 4; i++) {
65         int h = outlink->h;
66         h = i == 1 || i == 2 ? h>>priv->pix_desc->log2_chroma_h : h;
67         if (outpicref->data[i]) {
68             uint8_t *data = outpicref->data[i] +
69                 (outpicref->linesize[i] > 0 ? 0 : outpicref->linesize[i] * (h-1));
70             memset(data, 0, FFABS(outpicref->linesize[i]) * h);
71         }
72     }
73
74     /* copy palette */
75     if (priv->pix_desc->flags & PIX_FMT_PAL ||
76         priv->pix_desc->flags & PIX_FMT_PSEUDOPAL)
77         memcpy(outpicref->data[1], outpicref->data[1], 256*4);
78
79     avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
80 }
81
82 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
83 {
84     PixdescTestContext *priv = inlink->dst->priv;
85     AVFilterBufferRef *inpic    = inlink->cur_buf;
86     AVFilterBufferRef *outpic   = inlink->dst->outputs[0]->out_buf;
87     int i, c, w = inlink->w;
88
89     for (c = 0; c < priv->pix_desc->nb_components; c++) {
90         int w1 = c == 1 || c == 2 ? w>>priv->pix_desc->log2_chroma_w : w;
91         int h1 = c == 1 || c == 2 ? h>>priv->pix_desc->log2_chroma_h : h;
92         int y1 = c == 1 || c == 2 ? y>>priv->pix_desc->log2_chroma_h : y;
93
94         for (i = y1; i < y1 + h1; i++) {
95             av_read_image_line(priv->line,
96                                inpic->data,
97                                inpic->linesize,
98                                priv->pix_desc,
99                                0, i, c, w1, 0);
100
101             av_write_image_line(priv->line,
102                                 outpic->data,
103                                 outpic->linesize,
104                                 priv->pix_desc,
105                                 0, i, c, w1);
106         }
107     }
108
109     avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
110 }
111
112 AVFilter avfilter_vf_pixdesctest = {
113     .name        = "pixdesctest",
114     .description = NULL_IF_CONFIG_SMALL("Test pixel format definitions."),
115
116     .priv_size = sizeof(PixdescTestContext),
117     .uninit    = uninit,
118
119     .inputs    = (AVFilterPad[]) {{ .name            = "default",
120                                     .type            = AVMEDIA_TYPE_VIDEO,
121                                     .start_frame     = start_frame,
122                                     .draw_slice      = draw_slice,
123                                     .config_props    = config_props,
124                                     .min_perms       = AV_PERM_READ, },
125                                   { .name = NULL}},
126
127     .outputs   = (AVFilterPad[]) {{ .name            = "default",
128                                     .type            = AVMEDIA_TYPE_VIDEO, },
129                                   { .name = NULL}},
130 };