| /* |
| * Copyright (c) 2021 Paul B Mahol |
| * |
| * 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 |
| * Change the PTS/DTS timestamps. |
| */ |
| |
| #include "libavutil/opt.h" |
| #include "libavutil/eval.h" |
| |
| #include "avcodec.h" |
| #include "bsf.h" |
| #include "bsf_internal.h" |
| |
| static const char *const var_names[] = { |
| "N", ///< frame number (starting at zero) |
| "TS", |
| "POS", ///< original position in the file of the frame |
| "PREV_INPTS", ///< previous input PTS |
| "PREV_INDTS", ///< previous input DTS |
| "PREV_OUTPTS", ///< previous output PTS |
| "PREV_OUTDTS", ///< previous output DTS |
| "PTS", ///< original PTS in the file of the frame |
| "DTS", ///< original DTS in the file of the frame |
| "STARTPTS", ///< PTS at start of movie |
| "STARTDTS", ///< DTS at start of movie |
| "TB", ///< timebase of the stream |
| "SR", ///< sample rate of the stream |
| NULL |
| }; |
| |
| enum var_name { |
| VAR_N, |
| VAR_TS, |
| VAR_POS, |
| VAR_PREV_INPTS, |
| VAR_PREV_INDTS, |
| VAR_PREV_OUTPTS, |
| VAR_PREV_OUTDTS, |
| VAR_PTS, |
| VAR_DTS, |
| VAR_STARTPTS, |
| VAR_STARTDTS, |
| VAR_TB, |
| VAR_SR, |
| VAR_VARS_NB |
| }; |
| |
| typedef struct SetTSContext { |
| const AVClass *class; |
| |
| char *ts_str; |
| char *pts_str; |
| char *dts_str; |
| |
| int64_t frame_number; |
| |
| int64_t start_pts; |
| int64_t start_dts; |
| int64_t prev_inpts; |
| int64_t prev_indts; |
| int64_t prev_outpts; |
| int64_t prev_outdts; |
| |
| double var_values[VAR_VARS_NB]; |
| |
| AVExpr *ts_expr; |
| AVExpr *pts_expr; |
| AVExpr *dts_expr; |
| } SetTSContext; |
| |
| static int setts_init(AVBSFContext *ctx) |
| { |
| SetTSContext *s = ctx->priv_data; |
| int ret; |
| |
| if ((ret = av_expr_parse(&s->ts_expr, s->ts_str, |
| var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error while parsing ts expression '%s'\n", s->ts_str); |
| return ret; |
| } |
| |
| if (s->pts_str) { |
| if ((ret = av_expr_parse(&s->pts_expr, s->pts_str, |
| var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error while parsing pts expression '%s'\n", s->pts_str); |
| return ret; |
| } |
| } |
| |
| if (s->dts_str) { |
| if ((ret = av_expr_parse(&s->dts_expr, s->dts_str, |
| var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error while parsing dts expression '%s'\n", s->dts_str); |
| return ret; |
| } |
| } |
| |
| s->frame_number= 0; |
| s->start_pts = AV_NOPTS_VALUE; |
| s->start_dts = AV_NOPTS_VALUE; |
| s->prev_inpts = AV_NOPTS_VALUE; |
| s->prev_indts = AV_NOPTS_VALUE; |
| s->prev_outpts = AV_NOPTS_VALUE; |
| s->prev_outdts = AV_NOPTS_VALUE; |
| |
| return 0; |
| } |
| |
| static int setts_filter(AVBSFContext *ctx, AVPacket *pkt) |
| { |
| SetTSContext *s = ctx->priv_data; |
| int64_t new_ts, new_pts, new_dts; |
| int ret; |
| |
| ret = ff_bsf_get_packet_ref(ctx, pkt); |
| if (ret < 0) |
| return ret; |
| |
| if (s->start_pts == AV_NOPTS_VALUE) |
| s->start_pts = pkt->pts; |
| |
| if (s->start_dts == AV_NOPTS_VALUE) |
| s->start_dts = pkt->dts; |
| |
| s->var_values[VAR_N] = s->frame_number++; |
| s->var_values[VAR_TS] = pkt->dts; |
| s->var_values[VAR_POS] = pkt->pos; |
| s->var_values[VAR_PTS] = pkt->pts; |
| s->var_values[VAR_DTS] = pkt->dts; |
| s->var_values[VAR_PREV_INPTS] = s->prev_inpts; |
| s->var_values[VAR_PREV_INDTS] = s->prev_indts; |
| s->var_values[VAR_PREV_OUTPTS] = s->prev_outpts; |
| s->var_values[VAR_PREV_OUTDTS] = s->prev_outdts; |
| s->var_values[VAR_STARTPTS] = s->start_pts; |
| s->var_values[VAR_STARTDTS] = s->start_dts; |
| s->var_values[VAR_TB] = av_q2d(ctx->time_base_out); |
| s->var_values[VAR_SR] = ctx->par_in->sample_rate; |
| |
| new_ts = llrint(av_expr_eval(s->ts_expr, s->var_values, NULL)); |
| |
| if (s->pts_str) { |
| s->var_values[VAR_TS] = pkt->pts; |
| new_pts = llrint(av_expr_eval(s->pts_expr, s->var_values, NULL)); |
| } else { |
| new_pts = new_ts; |
| } |
| |
| if (s->dts_str) { |
| s->var_values[VAR_TS] = pkt->dts; |
| new_dts = llrint(av_expr_eval(s->dts_expr, s->var_values, NULL)); |
| } else { |
| new_dts = new_ts; |
| } |
| |
| s->var_values[VAR_PREV_INPTS] = pkt->pts; |
| s->var_values[VAR_PREV_INDTS] = pkt->dts; |
| s->var_values[VAR_PREV_OUTPTS] = new_pts; |
| s->var_values[VAR_PREV_OUTDTS] = new_dts; |
| |
| pkt->pts = new_pts; |
| pkt->dts = new_dts; |
| |
| return ret; |
| } |
| |
| static void setts_close(AVBSFContext *bsf) |
| { |
| SetTSContext *s = bsf->priv_data; |
| |
| av_expr_free(s->ts_expr); |
| s->ts_expr = NULL; |
| av_expr_free(s->pts_expr); |
| s->pts_expr = NULL; |
| av_expr_free(s->dts_expr); |
| s->dts_expr = NULL; |
| } |
| |
| #define OFFSET(x) offsetof(SetTSContext, x) |
| #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_BSF_PARAM) |
| |
| static const AVOption options[] = { |
| { "ts", "set expression for packet PTS and DTS", OFFSET(ts_str), AV_OPT_TYPE_STRING, {.str="TS"}, 0, 0, FLAGS }, |
| { "pts", "set expression for packet PTS", OFFSET(pts_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, |
| { "dts", "set expression for packet DTS", OFFSET(dts_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS }, |
| { NULL }, |
| }; |
| |
| static const AVClass setts_class = { |
| .class_name = "setts_bsf", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| const AVBitStreamFilter ff_setts_bsf = { |
| .name = "setts", |
| .priv_data_size = sizeof(SetTSContext), |
| .priv_class = &setts_class, |
| .init = setts_init, |
| .close = setts_close, |
| .filter = setts_filter, |
| }; |