diff options
Diffstat (limited to 'libavfilter/vf_reverse.c')
-rw-r--r-- | libavfilter/vf_reverse.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/libavfilter/vf_reverse.c b/libavfilter/vf_reverse.c new file mode 100644 index 0000000000..0d6dff2124 --- /dev/null +++ b/libavfilter/vf_reverse.c @@ -0,0 +1,142 @@ +/* + * Copyright (c) 2015 Derek Buitenhuis + * + * 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 "libavutil/opt.h" +#include "avfilter.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +#define DEFAULT_LENGTH 300 + +typedef struct ReverseContext { + int nb_frames; + AVFrame **frames; + unsigned int frames_size; + unsigned int pts_size; + int64_t *pts; + int flush_idx; +} ReverseContext; + +static av_cold int init(AVFilterContext *ctx) +{ + ReverseContext *s = ctx->priv; + + s->pts = av_fast_realloc(NULL, &s->pts_size, + DEFAULT_LENGTH * sizeof(*(s->pts))); + if (!s->pts) + return AVERROR(ENOMEM); + + s->frames = av_fast_realloc(NULL, &s->frames_size, + DEFAULT_LENGTH * sizeof(*(s->frames))); + if (!s->frames) { + av_freep(&s->pts); + return AVERROR(ENOMEM); + } + + return 0; +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + ReverseContext *s = ctx->priv; + + av_freep(&s->pts); + av_freep(&s->frames); +} + +static int config_output(AVFilterLink *outlink) +{ + outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP; + return 0; +} + +static int filter_frame(AVFilterLink *inlink, AVFrame *in) +{ + AVFilterContext *ctx = inlink->dst; + ReverseContext *s = ctx->priv; + + if (s->nb_frames + 1 > s->frames_size / sizeof(*(s->frames))) { + void *ptr; + + ptr = av_fast_realloc(s->pts, &s->pts_size, s->pts_size * 2); + if (!ptr) + return AVERROR(ENOMEM); + s->pts = ptr; + + ptr = av_fast_realloc(s->frames, &s->frames_size, s->frames_size * 2); + if (!ptr) + return AVERROR(ENOMEM); + s->frames = ptr; + } + + s->frames[s->nb_frames] = in; + s->pts[s->nb_frames] = in->pts; + s->nb_frames++; + + return 0; +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + ReverseContext *s = ctx->priv; + int ret; + + ret = ff_request_frame(ctx->inputs[0]); + + if (ret == AVERROR_EOF && s->nb_frames > 0) { + AVFrame *out = s->frames[s->nb_frames - 1]; + out->pts = s->pts[s->flush_idx++]; + ret = ff_filter_frame(outlink, out); + s->nb_frames--; + } + + return ret; +} + +static const AVFilterPad reverse_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad reverse_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .request_frame = request_frame, + .config_props = config_output, + }, + { NULL } +}; + +AVFilter ff_vf_reverse = { + .name = "reverse", + .description = NULL_IF_CONFIG_SMALL("Reverse a clip."), + .priv_size = sizeof(ReverseContext), + .init = init, + .uninit = uninit, + .inputs = reverse_inputs, + .outputs = reverse_outputs, +}; |