diff options
author | Stefano Sabatini <stefano.sabatini-lala@poste.it> | 2011-05-07 04:06:25 +0400 |
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committer | Anton Khirnov <anton@khirnov.net> | 2011-09-17 21:08:30 +0400 |
commit | d763fb7d47fdbd107ea65cdf511f2f21558f6610 (patch) | |
tree | a457c93b1fe72d53982d0a4f1bfcd955f1deb54b /libavfilter/vf_select.c | |
parent | 0e7efb9d23c3641d50caa288818e8c27647ce74d (diff) |
lavfi: add select filter
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Diffstat (limited to 'libavfilter/vf_select.c')
-rw-r--r-- | libavfilter/vf_select.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/libavfilter/vf_select.c b/libavfilter/vf_select.c new file mode 100644 index 0000000000..0ec443aec5 --- /dev/null +++ b/libavfilter/vf_select.c @@ -0,0 +1,353 @@ +/* + * Copyright (c) 2011 Stefano Sabatini + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; 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 "libavutil/mathematics.h" +#include "avfilter.h" + +static const char *var_names[] = { + "E", ///< Euler number + "PHI", ///< golden ratio + "PI", ///< greek pi + + "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_E, + VAR_PHI, + VAR_PI, + + 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_E] = M_E; + select->var_values[VAR_PHI] = M_PHI; + select->var_values[VAR_PI] = M_PI; + + 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 = (AVFilterPad[]) {{ .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .get_video_buffer = avfilter_null_get_video_buffer, + .config_props = config_input, + .start_frame = start_frame, + .draw_slice = draw_slice, + .end_frame = end_frame }, + { .name = NULL }}, + .outputs = (AVFilterPad[]) {{ .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .poll_frame = poll_frame, + .request_frame = request_frame, }, + { .name = NULL}}, +}; |