| /* |
| * Copyright (c) 2011 Stefano Sabatini |
| * |
| * 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 |
| * filter for selecting which frame passes in the filterchain |
| */ |
| |
| #include "libavutil/eval.h" |
| #include "libavutil/fifo.h" |
| #include "avfilter.h" |
| #include "video.h" |
| |
| static const char *const var_names[] = { |
| "TB", ///< timebase |
| |
| "pts", ///< original pts in the file of the frame |
| "start_pts", ///< first PTS in the stream, expressed in TB units |
| "prev_pts", ///< previous frame PTS |
| "prev_selected_pts", ///< previous selected frame PTS |
| |
| "t", ///< first PTS in seconds |
| "start_t", ///< first PTS in the stream, expressed in seconds |
| "prev_t", ///< previous frame time |
| "prev_selected_t", ///< previously selected time |
| |
| "pict_type", ///< the type of picture in the movie |
| "I", |
| "P", |
| "B", |
| "S", |
| "SI", |
| "SP", |
| "BI", |
| |
| "interlace_type", ///< the frame interlace type |
| "PROGRESSIVE", |
| "TOPFIRST", |
| "BOTTOMFIRST", |
| |
| "n", ///< frame number (starting from zero) |
| "selected_n", ///< selected frame number (starting from zero) |
| "prev_selected_n", ///< number of the last selected frame |
| |
| "key", ///< tell if the frame is a key frame |
| "pos", ///< original position in the file of the frame |
| |
| NULL |
| }; |
| |
| enum var_name { |
| VAR_TB, |
| |
| VAR_PTS, |
| VAR_START_PTS, |
| VAR_PREV_PTS, |
| VAR_PREV_SELECTED_PTS, |
| |
| VAR_T, |
| VAR_START_T, |
| VAR_PREV_T, |
| VAR_PREV_SELECTED_T, |
| |
| VAR_PICT_TYPE, |
| VAR_PICT_TYPE_I, |
| VAR_PICT_TYPE_P, |
| VAR_PICT_TYPE_B, |
| VAR_PICT_TYPE_S, |
| VAR_PICT_TYPE_SI, |
| VAR_PICT_TYPE_SP, |
| VAR_PICT_TYPE_BI, |
| |
| VAR_INTERLACE_TYPE, |
| VAR_INTERLACE_TYPE_P, |
| VAR_INTERLACE_TYPE_T, |
| VAR_INTERLACE_TYPE_B, |
| |
| VAR_N, |
| VAR_SELECTED_N, |
| VAR_PREV_SELECTED_N, |
| |
| VAR_KEY, |
| VAR_POS, |
| |
| VAR_VARS_NB |
| }; |
| |
| #define FIFO_SIZE 8 |
| |
| typedef struct { |
| AVExpr *expr; |
| double var_values[VAR_VARS_NB]; |
| double select; |
| int cache_frames; |
| AVFifoBuffer *pending_frames; ///< FIFO buffer of video frames |
| } SelectContext; |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| SelectContext *select = ctx->priv; |
| int ret; |
| |
| if ((ret = av_expr_parse(&select->expr, args ? args : "1", |
| var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", args); |
| return ret; |
| } |
| |
| select->pending_frames = av_fifo_alloc(FIFO_SIZE*sizeof(AVFilterBufferRef*)); |
| if (!select->pending_frames) { |
| av_log(ctx, AV_LOG_ERROR, "Failed to allocate pending frames buffer.\n"); |
| return AVERROR(ENOMEM); |
| } |
| return 0; |
| } |
| |
| #define INTERLACE_TYPE_P 0 |
| #define INTERLACE_TYPE_T 1 |
| #define INTERLACE_TYPE_B 2 |
| |
| static int config_input(AVFilterLink *inlink) |
| { |
| SelectContext *select = inlink->dst->priv; |
| |
| select->var_values[VAR_N] = 0.0; |
| select->var_values[VAR_SELECTED_N] = 0.0; |
| |
| select->var_values[VAR_TB] = av_q2d(inlink->time_base); |
| |
| select->var_values[VAR_PREV_PTS] = NAN; |
| select->var_values[VAR_PREV_SELECTED_PTS] = NAN; |
| select->var_values[VAR_PREV_SELECTED_T] = NAN; |
| select->var_values[VAR_START_PTS] = NAN; |
| select->var_values[VAR_START_T] = NAN; |
| |
| select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I; |
| select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P; |
| select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B; |
| select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI; |
| select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP; |
| |
| select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P; |
| select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T; |
| select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B; |
| |
| return 0; |
| } |
| |
| #define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d)) |
| #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)) |
| |
| static int select_frame(AVFilterContext *ctx, AVFilterBufferRef *picref) |
| { |
| SelectContext *select = ctx->priv; |
| AVFilterLink *inlink = ctx->inputs[0]; |
| double res; |
| |
| if (isnan(select->var_values[VAR_START_PTS])) |
| select->var_values[VAR_START_PTS] = TS2D(picref->pts); |
| if (isnan(select->var_values[VAR_START_T])) |
| select->var_values[VAR_START_T] = TS2D(picref->pts) * av_q2d(inlink->time_base); |
| |
| select->var_values[VAR_PTS] = TS2D(picref->pts); |
| select->var_values[VAR_T ] = TS2D(picref->pts) * av_q2d(inlink->time_base); |
| select->var_values[VAR_POS] = picref->pos == -1 ? NAN : picref->pos; |
| select->var_values[VAR_PREV_PTS] = TS2D(picref ->pts); |
| |
| select->var_values[VAR_INTERLACE_TYPE] = |
| !picref->video->interlaced ? INTERLACE_TYPE_P : |
| picref->video->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B; |
| select->var_values[VAR_PICT_TYPE] = picref->video->pict_type; |
| |
| res = av_expr_eval(select->expr, select->var_values, NULL); |
| av_log(inlink->dst, AV_LOG_DEBUG, |
| "n:%d pts:%d t:%f pos:%d interlace_type:%c key:%d pict_type:%c " |
| "-> select:%f\n", |
| (int)select->var_values[VAR_N], |
| (int)select->var_values[VAR_PTS], |
| select->var_values[VAR_T], |
| (int)select->var_values[VAR_POS], |
| select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' : |
| select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' : |
| select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?', |
| (int)select->var_values[VAR_KEY], |
| av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]), |
| res); |
| |
| select->var_values[VAR_N] += 1.0; |
| |
| if (res) { |
| select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N]; |
| select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS]; |
| select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T]; |
| select->var_values[VAR_SELECTED_N] += 1.0; |
| } |
| return res; |
| } |
| |
| static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) |
| { |
| SelectContext *select = inlink->dst->priv; |
| |
| select->select = select_frame(inlink->dst, picref); |
| if (select->select) { |
| /* frame was requested through poll_frame */ |
| if (select->cache_frames) { |
| if (!av_fifo_space(select->pending_frames)) |
| av_log(inlink->dst, AV_LOG_ERROR, |
| "Buffering limit reached, cannot cache more frames\n"); |
| else |
| av_fifo_generic_write(select->pending_frames, &picref, |
| sizeof(picref), NULL); |
| return; |
| } |
| avfilter_start_frame(inlink->dst->outputs[0], avfilter_ref_buffer(picref, ~0)); |
| } |
| } |
| |
| static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) |
| { |
| SelectContext *select = inlink->dst->priv; |
| |
| if (select->select && !select->cache_frames) |
| avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir); |
| } |
| |
| static void end_frame(AVFilterLink *inlink) |
| { |
| SelectContext *select = inlink->dst->priv; |
| AVFilterBufferRef *picref = inlink->cur_buf; |
| |
| if (select->select) { |
| if (select->cache_frames) |
| return; |
| avfilter_end_frame(inlink->dst->outputs[0]); |
| } |
| avfilter_unref_buffer(picref); |
| } |
| |
| static int request_frame(AVFilterLink *outlink) |
| { |
| AVFilterContext *ctx = outlink->src; |
| SelectContext *select = ctx->priv; |
| AVFilterLink *inlink = outlink->src->inputs[0]; |
| select->select = 0; |
| |
| if (av_fifo_size(select->pending_frames)) { |
| AVFilterBufferRef *picref; |
| av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL); |
| avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0)); |
| avfilter_draw_slice(outlink, 0, outlink->h, 1); |
| avfilter_end_frame(outlink); |
| avfilter_unref_buffer(picref); |
| return 0; |
| } |
| |
| while (!select->select) { |
| int ret = avfilter_request_frame(inlink); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int poll_frame(AVFilterLink *outlink) |
| { |
| SelectContext *select = outlink->src->priv; |
| AVFilterLink *inlink = outlink->src->inputs[0]; |
| int count, ret; |
| |
| if (!av_fifo_size(select->pending_frames)) { |
| if ((count = avfilter_poll_frame(inlink)) <= 0) |
| return count; |
| /* request frame from input, and apply select condition to it */ |
| select->cache_frames = 1; |
| while (count-- && av_fifo_space(select->pending_frames)) { |
| ret = avfilter_request_frame(inlink); |
| if (ret < 0) |
| break; |
| } |
| select->cache_frames = 0; |
| } |
| |
| return av_fifo_size(select->pending_frames)/sizeof(AVFilterBufferRef *); |
| } |
| |
| static av_cold void uninit(AVFilterContext *ctx) |
| { |
| SelectContext *select = ctx->priv; |
| AVFilterBufferRef *picref; |
| |
| av_expr_free(select->expr); |
| select->expr = NULL; |
| |
| while (select->pending_frames && |
| av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL) == sizeof(picref)) |
| avfilter_unref_buffer(picref); |
| av_fifo_free(select->pending_frames); |
| select->pending_frames = NULL; |
| } |
| |
| AVFilter avfilter_vf_select = { |
| .name = "select", |
| .description = NULL_IF_CONFIG_SMALL("Select frames to pass in output."), |
| .init = init, |
| .uninit = uninit, |
| |
| .priv_size = sizeof(SelectContext), |
| |
| .inputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .get_video_buffer = ff_null_get_video_buffer, |
| .config_props = config_input, |
| .start_frame = start_frame, |
| .draw_slice = draw_slice, |
| .end_frame = end_frame }, |
| { .name = NULL }}, |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .poll_frame = poll_frame, |
| .request_frame = request_frame, }, |
| { .name = NULL}}, |
| }; |