diff options
Diffstat (limited to 'libavfilter/f_select.c')
-rw-r--r-- | libavfilter/f_select.c | 511 |
1 files changed, 511 insertions, 0 deletions
diff --git a/libavfilter/f_select.c b/libavfilter/f_select.c new file mode 100644 index 0000000..4881a85 --- /dev/null +++ b/libavfilter/f_select.c @@ -0,0 +1,511 @@ +/* + * 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 "libavutil/internal.h" +#include "libavutil/opt.h" +#include "avfilter.h" +#include "audio.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +#if CONFIG_AVCODEC +#include "libavcodec/dsputil.h" +#endif + +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", + + "consumed_samples_n",///< number of samples consumed by the filter (only audio) + "samples_n", ///< number of samples in the current frame (only audio) + "sample_rate", ///< sample rate (only audio) + + "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 + + "scene", + + 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_CONSUMED_SAMPLES_N, + VAR_SAMPLES_N, + VAR_SAMPLE_RATE, + + VAR_N, + VAR_SELECTED_N, + VAR_PREV_SELECTED_N, + + VAR_KEY, + VAR_POS, + + VAR_SCENE, + + VAR_VARS_NB +}; + +typedef struct { + const AVClass *class; + AVExpr *expr; + char *expr_str; + double var_values[VAR_VARS_NB]; + int do_scene_detect; ///< 1 if the expression requires scene detection variables, 0 otherwise +#if CONFIG_AVCODEC + AVCodecContext *avctx; ///< codec context required for the DSPContext (scene detect only) + DSPContext c; ///< context providing optimized SAD methods (scene detect only) + double prev_mafd; ///< previous MAFD (scene detect only) +#endif + AVFilterBufferRef *prev_picref; ///< previous frame (scene detect only) + double select; +} SelectContext; + +#define OFFSET(x) offsetof(SelectContext, x) +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM +static const AVOption options[] = { + { "expr", "set selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str = "1"}, 0, 0, FLAGS }, + { "e", "set selection expression", OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str = "1"}, 0, 0, FLAGS }, + {NULL}, +}; + +static av_cold int init(AVFilterContext *ctx, const char *args, const AVClass *class) +{ + SelectContext *select = ctx->priv; + const char *shorthand[] = { "expr", NULL }; + int ret; + + select->class = class; + av_opt_set_defaults(select); + + if ((ret = av_opt_set_from_string(select, args, shorthand, "=", ":")) < 0) + return ret; + + if ((ret = av_expr_parse(&select->expr, select->expr_str, + var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { + av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", select->expr_str); + return ret; + } + select->do_scene_detect = !!strstr(select->expr_str, "scene"); + + 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; + + select->var_values[VAR_PICT_TYPE] = NAN; + select->var_values[VAR_INTERLACE_TYPE] = NAN; + select->var_values[VAR_SCENE] = NAN; + select->var_values[VAR_CONSUMED_SAMPLES_N] = NAN; + select->var_values[VAR_SAMPLES_N] = NAN; + + select->var_values[VAR_SAMPLE_RATE] = + inlink->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN; + +#if CONFIG_AVCODEC + if (select->do_scene_detect) { + select->avctx = avcodec_alloc_context3(NULL); + if (!select->avctx) + return AVERROR(ENOMEM); + dsputil_init(&select->c, select->avctx); + } +#endif + return 0; +} + +#if CONFIG_AVCODEC +static double get_scene_score(AVFilterContext *ctx, AVFilterBufferRef *picref) +{ + double ret = 0; + SelectContext *select = ctx->priv; + AVFilterBufferRef *prev_picref = select->prev_picref; + + if (prev_picref && + picref->video->h == prev_picref->video->h && + picref->video->w == prev_picref->video->w && + picref->linesize[0] == prev_picref->linesize[0]) { + int x, y, nb_sad = 0; + int64_t sad = 0; + double mafd, diff; + uint8_t *p1 = picref->data[0]; + uint8_t *p2 = prev_picref->data[0]; + const int linesize = picref->linesize[0]; + + for (y = 0; y < picref->video->h - 8; y += 8) { + for (x = 0; x < picref->video->w*3 - 8; x += 8) { + sad += select->c.sad[1](select, p1 + x, p2 + x, + linesize, 8); + nb_sad += 8 * 8; + } + p1 += 8 * linesize; + p2 += 8 * linesize; + } + emms_c(); + mafd = nb_sad ? sad / nb_sad : 0; + diff = fabs(mafd - select->prev_mafd); + ret = av_clipf(FFMIN(mafd, diff) / 100., 0, 1); + select->prev_mafd = mafd; + avfilter_unref_buffer(prev_picref); + } + select->prev_picref = avfilter_ref_buffer(picref, ~0); + return ret; +} +#endif + +#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 *ref) +{ + 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(ref->pts); + if (isnan(select->var_values[VAR_START_T])) + select->var_values[VAR_START_T] = TS2D(ref->pts) * av_q2d(inlink->time_base); + + select->var_values[VAR_PTS] = TS2D(ref->pts); + select->var_values[VAR_T ] = TS2D(ref->pts) * av_q2d(inlink->time_base); + select->var_values[VAR_POS] = ref->pos == -1 ? NAN : ref->pos; + select->var_values[VAR_PREV_PTS] = TS2D(ref ->pts); + + switch (inlink->type) { + case AVMEDIA_TYPE_AUDIO: + select->var_values[VAR_SAMPLES_N] = ref->audio->nb_samples; + break; + + case AVMEDIA_TYPE_VIDEO: + select->var_values[VAR_INTERLACE_TYPE] = + !ref->video->interlaced ? INTERLACE_TYPE_P : + ref->video->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B; + select->var_values[VAR_PICT_TYPE] = ref->video->pict_type; +#if CONFIG_AVCODEC + if (select->do_scene_detect) { + char buf[32]; + select->var_values[VAR_SCENE] = get_scene_score(ctx, ref); + // TODO: document metadata + snprintf(buf, sizeof(buf), "%f", select->var_values[VAR_SCENE]); + av_dict_set(&ref->metadata, "lavfi.scene_score", buf, 0); + } +#endif + break; + } + + 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 key:%d", + (int)select->var_values[VAR_N], + (int)select->var_values[VAR_PTS], + select->var_values[VAR_T], + (int)select->var_values[VAR_POS], + (int)select->var_values[VAR_KEY]); + + switch (inlink->type) { + case AVMEDIA_TYPE_VIDEO: + av_log(inlink->dst, AV_LOG_DEBUG, " interlace_type:%c pict_type:%c scene:%f", + 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' : '?', + av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]), + select->var_values[VAR_SCENE]); + break; + case AVMEDIA_TYPE_AUDIO: + av_log(inlink->dst, AV_LOG_DEBUG, " samples_n:%d consumed_samples_n:%d", + (int)select->var_values[VAR_SAMPLES_N], + (int)select->var_values[VAR_CONSUMED_SAMPLES_N]); + break; + } + + av_log(inlink->dst, AV_LOG_DEBUG, " -> select:%f\n", res); + + 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; + if (inlink->type == AVMEDIA_TYPE_AUDIO) + select->var_values[VAR_CONSUMED_SAMPLES_N] += ref->audio->nb_samples; + } + + select->var_values[VAR_N] += 1.0; + + return res; +} + +static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *frame) +{ + SelectContext *select = inlink->dst->priv; + + select->select = select_frame(inlink->dst, frame); + if (select->select) + return ff_filter_frame(inlink->dst->outputs[0], frame); + + avfilter_unref_bufferp(&frame); + return 0; +} + +static int request_frame(AVFilterLink *outlink) +{ + AVFilterContext *ctx = outlink->src; + SelectContext *select = ctx->priv; + AVFilterLink *inlink = outlink->src->inputs[0]; + select->select = 0; + + do { + int ret = ff_request_frame(inlink); + if (ret < 0) + return ret; + } while (!select->select); + + return 0; +} + +static av_cold void uninit(AVFilterContext *ctx) +{ + SelectContext *select = ctx->priv; + + av_expr_free(select->expr); + select->expr = NULL; + av_opt_free(select); + +#if CONFIG_AVCODEC + if (select->do_scene_detect) { + avfilter_unref_bufferp(&select->prev_picref); + if (select->avctx) { + avcodec_close(select->avctx); + av_freep(&select->avctx); + } + } +#endif +} + +static int query_formats(AVFilterContext *ctx) +{ + SelectContext *select = ctx->priv; + + if (!select->do_scene_detect) { + return ff_default_query_formats(ctx); + } else { + static const enum AVPixelFormat pix_fmts[] = { + AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, + AV_PIX_FMT_NONE + }; + ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); + } + return 0; +} + +#if CONFIG_ASELECT_FILTER + +#define aselect_options options +AVFILTER_DEFINE_CLASS(aselect); + +static av_cold int aselect_init(AVFilterContext *ctx, const char *args) +{ + SelectContext *select = ctx->priv; + int ret; + + if ((ret = init(ctx, args, &aselect_class)) < 0) + return ret; + + if (select->do_scene_detect) { + av_log(ctx, AV_LOG_ERROR, "Scene detection is ignored in aselect filter\n"); + return AVERROR(EINVAL); + } + + return 0; +} + +static const AVFilterPad avfilter_af_aselect_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + .get_audio_buffer = ff_null_get_audio_buffer, + .config_props = config_input, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad avfilter_af_aselect_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_AUDIO, + }, + { NULL } +}; + +AVFilter avfilter_af_aselect = { + .name = "aselect", + .description = NULL_IF_CONFIG_SMALL("Select audio frames to pass in output."), + .init = aselect_init, + .uninit = uninit, + .priv_size = sizeof(SelectContext), + .inputs = avfilter_af_aselect_inputs, + .outputs = avfilter_af_aselect_outputs, + .priv_class = &aselect_class, +}; +#endif /* CONFIG_ASELECT_FILTER */ + +#if CONFIG_SELECT_FILTER + +#define select_options options +AVFILTER_DEFINE_CLASS(select); + +static av_cold int select_init(AVFilterContext *ctx, const char *args) +{ + SelectContext *select = ctx->priv; + int ret; + + if ((ret = init(ctx, args, &select_class)) < 0) + return ret; + + if (select->do_scene_detect && !CONFIG_AVCODEC) { + av_log(ctx, AV_LOG_ERROR, "Scene detection is not available without libavcodec.\n"); + return AVERROR(EINVAL); + } + + return 0; +} + +static const AVFilterPad avfilter_vf_select_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .get_video_buffer = ff_null_get_video_buffer, + .min_perms = AV_PERM_PRESERVE, + .config_props = config_input, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad avfilter_vf_select_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .request_frame = request_frame, + }, + { NULL } +}; + +AVFilter avfilter_vf_select = { + .name = "select", + .description = NULL_IF_CONFIG_SMALL("Select video frames to pass in output."), + .init = select_init, + .uninit = uninit, + .query_formats = query_formats, + + .priv_size = sizeof(SelectContext), + + .inputs = avfilter_vf_select_inputs, + .outputs = avfilter_vf_select_outputs, + .priv_class = &select_class, +}; +#endif /* CONFIG_SELECT_FILTER */ |