libavfilter/vsrc_buffer.c

   1 /*
   2  * Copyright (c) 2008 Vitor Sessak
   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  * memory buffer source filter
  24  */
  25
  26 #include "avfilter.h"
  27 #include "vsrc_buffer.h"
  28 #include "libavutil/imgutils.h"
  29
  30 typedef struct {
  31     int64_t           pts;
  32     AVFrame           frame;
  33     int               has_frame;
  34     int               h, w;
  35     enum PixelFormat  pix_fmt;
  36     AVRational        time_base;     ///< time_base to set in the output link
  37     AVRational        pixel_aspect;
  38 } BufferSourceContext;
  39
  40 int av_vsrc_buffer_add_frame(AVFilterContext *buffer_filter, AVFrame *frame,
  41                              int64_t pts, AVRational pixel_aspect)
  42 {
  43     BufferSourceContext *c = buffer_filter->priv;
  44
  45     if (c->has_frame) {
  46         av_log(buffer_filter, AV_LOG_ERROR,
  47                "Buffering several frames is not supported. "
  48                "Please consume all available frames before adding a new one.\n"
  49             );
  50         //return -1;
  51     }
  52
  53     memcpy(c->frame.data    , frame->data    , sizeof(frame->data));
  54     memcpy(c->frame.linesize, frame->linesize, sizeof(frame->linesize));
  55     c->frame.interlaced_frame= frame->interlaced_frame;
  56     c->frame.top_field_first = frame->top_field_first;
  57     c->frame.key_frame = frame->key_frame;
  58     c->frame.pict_type = frame->pict_type;
  59     c->pts = pts;
  60     c->pixel_aspect = pixel_aspect;
  61     c->has_frame = 1;
  62
  63     return 0;
  64 }
  65
  66 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
  67 {
  68     BufferSourceContext *c = ctx->priv;
  69     char pix_fmt_str[128];
  70     int n = 0;
  71
  72     if (!args ||
  73         (n = sscanf(args, "%d:%d:%127[^:]:%d:%d:%d:%d", &c->w, &c->h, pix_fmt_str,
  74                     &c->time_base.num, &c->time_base.den,
  75                     &c->pixel_aspect.num, &c->pixel_aspect.den)) != 7) {
  76         av_log(ctx, AV_LOG_ERROR, "Expected 7 arguments, but %d found in '%s'\n", n, args);
  77         return AVERROR(EINVAL);
  78     }
  79     if ((c->pix_fmt = av_get_pix_fmt(pix_fmt_str)) == PIX_FMT_NONE) {
  80         char *tail;
  81         c->pix_fmt = strtol(pix_fmt_str, &tail, 10);
  82         if (*tail || c->pix_fmt < 0 || c->pix_fmt >= PIX_FMT_NB) {
  83             av_log(ctx, AV_LOG_ERROR, "Invalid pixel format string '%s'\n", pix_fmt_str);
  84             return AVERROR(EINVAL);
  85         }
  86     }
  87
  88     av_log(ctx, AV_LOG_INFO, "w:%d h:%d pixfmt:%s\n", c->w, c->h, av_pix_fmt_descriptors[c->pix_fmt].name);
  89     return 0;
  90 }
  91
  92 static int query_formats(AVFilterContext *ctx)
  93 {
  94     BufferSourceContext *c = ctx->priv;
  95     enum PixelFormat pix_fmts[] = { c->pix_fmt, PIX_FMT_NONE };
  96
  97     avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
  98     return 0;
  99 }
 100
 101 static int config_props(AVFilterLink *link)
 102 {
 103     BufferSourceContext *c = link->src->priv;
 104
 105     link->w = c->w;
 106     link->h = c->h;
 107     link->sample_aspect_ratio = c->pixel_aspect;
 108     link->time_base = c->time_base;
 109
 110     return 0;
 111 }
 112
 113 static int request_frame(AVFilterLink *link)
 114 {
 115     BufferSourceContext *c = link->src->priv;
 116     AVFilterBufferRef *picref;
 117
 118     if (!c->has_frame) {
 119         av_log(link->src, AV_LOG_ERROR,
 120                "request_frame() called with no available frame!\n");
 121         //return -1;
 122     }
 123
 124     /* This picture will be needed unmodified later for decoding the next
 125      * frame */
 126     picref = avfilter_get_video_buffer(link, AV_PERM_WRITE | AV_PERM_PRESERVE |
 127                                        AV_PERM_REUSE2,
 128                                        link->w, link->h);
 129
 130     av_image_copy(picref->data, picref->linesize,
 131                   c->frame.data, c->frame.linesize,
 132                   picref->format, link->w, link->h);
 133
 134     avfilter_copy_frame_props(picref, &c->frame);
 135     picref->pts                    = c->pts;
 136     picref->video->pixel_aspect    = c->pixel_aspect;
 137     avfilter_start_frame(link, avfilter_ref_buffer(picref, ~0));
 138     avfilter_draw_slice(link, 0, link->h, 1);
 139     avfilter_end_frame(link);
 140     avfilter_unref_buffer(picref);
 141
 142     c->has_frame = 0;
 143
 144     return 0;
 145 }
 146
 147 static int poll_frame(AVFilterLink *link)
 148 {
 149     BufferSourceContext *c = link->src->priv;
 150     return !!(c->has_frame);
 151 }
 152
 153 AVFilter avfilter_vsrc_buffer = {
 154     .name      = "buffer",
 155     .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them accessible to the filterchain."),
 156     .priv_size = sizeof(BufferSourceContext),
 157     .query_formats = query_formats,
 158
 159     .init      = init,
 160
 161     .inputs    = (AVFilterPad[]) {{ .name = NULL }},
 162     .outputs   = (AVFilterPad[]) {{ .name            = "default",
 163                                     .type            = AVMEDIA_TYPE_VIDEO,
 164                                     .request_frame   = request_frame,
 165                                     .poll_frame      = poll_frame,
 166                                     .config_props    = config_props, },
 167                                   { .name = NULL}},
 168 };