libavfilter/vsrc_buffer.c

   1 /*
   2  * Memory buffer source filter
   3  * Copyright (c) 2008 Vitor Sessak
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "avfilter.h"
  23 #include "vsrc_buffer.h"
  24
  25 typedef struct {
  26     int64_t           pts;
  27     AVFrame           frame;
  28     int               has_frame;
  29     int               h, w, pix_fmt;
  30     AVRational        pixel_aspect;
  31 } BufferSourceContext;
  32
  33
  34 int av_vsrc_buffer_add_frame(AVFilterContext *buffer_filter, AVFrame *frame,
  35                              int64_t pts, AVRational pixel_aspect)
  36 {
  37     BufferSourceContext *c = buffer_filter->priv;
  38
  39     if (c->has_frame) {
  40         av_log(buffer_filter, AV_LOG_ERROR,
  41                "Buffering several frames is not supported. "
  42                "Please consume all available frames before adding a new one.\n"
  43             );
  44         //return -1;
  45     }
  46
  47     memcpy(c->frame.data    , frame->data    , sizeof(frame->data));
  48     memcpy(c->frame.linesize, frame->linesize, sizeof(frame->linesize));
  49     c->frame.interlaced_frame= frame->interlaced_frame;
  50     c->frame.top_field_first = frame->top_field_first;
  51     c->pts = pts;
  52     c->pixel_aspect = pixel_aspect;
  53     c->has_frame = 1;
  54
  55     return 0;
  56 }
  57
  58 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
  59 {
  60     BufferSourceContext *c = ctx->priv;
  61
  62     if(args && sscanf(args, "%d:%d:%d", &c->w, &c->h, &c->pix_fmt) == 3)
  63         return 0;
  64
  65     av_log(ctx, AV_LOG_ERROR, "init() expected 3 arguments:'%s'\n", args);
  66     return -1;
  67 }
  68
  69 static int query_formats(AVFilterContext *ctx)
  70 {
  71     BufferSourceContext *c = ctx->priv;
  72     enum PixelFormat pix_fmts[] = { c->pix_fmt, PIX_FMT_NONE };
  73
  74     avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
  75     return 0;
  76 }
  77
  78 static int config_props(AVFilterLink *link)
  79 {
  80     BufferSourceContext *c = link->src->priv;
  81
  82     link->w = c->w;
  83     link->h = c->h;
  84
  85     return 0;
  86 }
  87
  88
  89 static int request_frame(AVFilterLink *link)
  90 {
  91     BufferSourceContext *c = link->src->priv;
  92     AVFilterPicRef *picref;
  93
  94     if (!c->has_frame) {
  95         av_log(link->src, AV_LOG_ERROR,
  96                "request_frame() called with no available frame!\n");
  97         //return -1;
  98     }
  99
 100     /* This picture will be needed unmodified later for decoding the next
 101      * frame */
 102     picref = avfilter_get_video_buffer(link, AV_PERM_WRITE | AV_PERM_PRESERVE |
 103                                        AV_PERM_REUSE2,
 104                                        link->w, link->h);
 105
 106     av_picture_copy((AVPicture *)&picref->data, (AVPicture *)&c->frame,
 107                     picref->pic->format, link->w, link->h);
 108
 109     picref->pts = c->pts;
 110     picref->pixel_aspect = c->pixel_aspect;
 111     picref->interlaced      = c->frame.interlaced_frame;
 112     picref->top_field_first = c->frame.top_field_first;
 113     avfilter_start_frame(link, avfilter_ref_pic(picref, ~0));
 114     avfilter_draw_slice(link, 0, link->h, 1);
 115     avfilter_end_frame(link);
 116     avfilter_unref_pic(picref);
 117
 118     c->has_frame = 0;
 119
 120     return 0;
 121 }
 122
 123 static int poll_frame(AVFilterLink *link)
 124 {
 125     BufferSourceContext *c = link->src->priv;
 126     return !!(c->has_frame);
 127 }
 128
 129 AVFilter avfilter_vsrc_buffer =
 130 {
 131     .name      = "buffer",
 132     .priv_size = sizeof(BufferSourceContext),
 133     .query_formats = query_formats,
 134
 135     .init      = init,
 136
 137     .inputs    = (AVFilterPad[]) {{ .name = NULL }},
 138     .outputs   = (AVFilterPad[]) {{ .name            = "default",
 139                                     .type            = AVMEDIA_TYPE_VIDEO,
 140                                     .request_frame   = request_frame,
 141                                     .poll_frame      = poll_frame,
 142                                     .config_props    = config_props, },
 143                                   { .name = NULL}},
 144 };