2011-06-20 22:33:37 +00:00
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/*
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* Copyright (c) 2010 Nicolas George
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* Copyright (c) 2011 Stefano Sabatini
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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/**
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* @file
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* API example for decoding and filtering
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*/
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#define _XOPEN_SOURCE 600 /* for usleep */
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libavfilter/avfiltergraph.h>
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#include <libavfilter/vsrc_buffer.h>
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const char *filter_descr = "scale=78:24";
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static AVFormatContext *fmt_ctx;
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static AVCodecContext *dec_ctx;
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AVFilterContext *buffersink_ctx;
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AVFilterContext *buffersrc_ctx;
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AVFilterGraph *filter_graph;
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static int video_stream_index = -1;
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static int64_t last_pts = AV_NOPTS_VALUE;
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static int open_input_file(const char *filename)
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{
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int ret, i;
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AVCodec *dec;
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if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
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return ret;
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}
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if ((ret = av_find_stream_info(fmt_ctx)) < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
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return ret;
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}
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/* select the video stream */
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ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0);
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if (ret < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n");
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return ret;
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}
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video_stream_index = ret;
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dec_ctx = fmt_ctx->streams[video_stream_index]->codec;
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/* init the video decoder */
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if ((ret = avcodec_open(dec_ctx, dec)) < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n");
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return ret;
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}
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return 0;
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}
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static int init_filters(const char *filters_descr)
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{
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char args[512];
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int ret;
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AVFilter *buffersrc = avfilter_get_by_name("buffer");
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AVFilter *buffersink = avfilter_get_by_name("buffersink");
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AVFilterInOut *outputs = avfilter_inout_alloc();
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AVFilterInOut *inputs = avfilter_inout_alloc();
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enum PixelFormat pix_fmts[] = { PIX_FMT_GRAY8, PIX_FMT_NONE };
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filter_graph = avfilter_graph_alloc();
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/* buffer video source: the decoded frames from the decoder will be inserted here. */
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snprintf(args, sizeof(args), "%d:%d:%d:%d:%d:%d:%d",
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dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
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dec_ctx->time_base.num, dec_ctx->time_base.den,
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dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
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ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
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args, NULL, filter_graph);
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if (ret < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
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return ret;
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}
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/* buffer video sink: to terminate the filter chain. */
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ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
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NULL, pix_fmts, filter_graph);
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if (ret < 0) {
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av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
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return ret;
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}
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/* Endpoints for the filter graph. */
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outputs->name = av_strdup("in");
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outputs->filter_ctx = buffersrc_ctx;
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outputs->pad_idx = 0;
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outputs->next = NULL;
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inputs->name = av_strdup("out");
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inputs->filter_ctx = buffersink_ctx;
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inputs->pad_idx = 0;
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inputs->next = NULL;
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if ((ret = avfilter_graph_parse(filter_graph, filter_descr,
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&inputs, &outputs, NULL)) < 0)
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return ret;
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if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
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return ret;
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}
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static void display_picref(AVFilterBufferRef *picref, AVRational time_base)
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{
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int x, y;
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uint8_t *p0, *p;
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int64_t delay;
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if (picref->pts != AV_NOPTS_VALUE) {
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if (last_pts != AV_NOPTS_VALUE) {
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/* sleep roughly the right amount of time;
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* usleep is in microseconds, just like AV_TIME_BASE. */
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delay = av_rescale_q(picref->pts - last_pts,
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time_base, AV_TIME_BASE_Q);
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if (delay > 0 && delay < 1000000)
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usleep(delay);
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}
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last_pts = picref->pts;
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}
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/* Trivial ASCII grayscale display. */
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p0 = picref->data[0];
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puts("\033c");
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for (y = 0; y < picref->video->h; y++) {
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p = p0;
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for (x = 0; x < picref->video->w; x++)
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putchar(" .-+#"[*(p++) / 52]);
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putchar('\n');
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p0 += picref->linesize[0];
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}
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fflush(stdout);
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}
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int main(int argc, char **argv)
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{
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int ret;
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AVPacket packet;
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AVFrame frame;
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int got_frame;
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if (argc != 2) {
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fprintf(stderr, "Usage: %s file\n", argv[0]);
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exit(1);
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}
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avcodec_register_all();
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av_register_all();
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avfilter_register_all();
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2011-11-21 06:50:03 +00:00
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if ((ret = open_input_file(argv[1])) < 0)
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2011-06-20 22:33:37 +00:00
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goto end;
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if ((ret = init_filters(filter_descr)) < 0)
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goto end;
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/* read all packets */
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while (1) {
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AVFilterBufferRef *picref;
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if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
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break;
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if (packet.stream_index == video_stream_index) {
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avcodec_get_frame_defaults(&frame);
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got_frame = 0;
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ret = avcodec_decode_video2(dec_ctx, &frame, &got_frame, &packet);
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av_free_packet(&packet);
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if (ret < 0) {
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av_log(NULL, AV_LOG_ERROR, "Error decoding video\n");
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break;
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}
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if (got_frame) {
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if (frame.pts == AV_NOPTS_VALUE)
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frame.pts = frame.pkt_dts == AV_NOPTS_VALUE ?
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frame.pkt_dts : frame.pkt_pts;
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/* push the decoded frame into the filtergraph */
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av_vsrc_buffer_add_frame(buffersrc_ctx, &frame);
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/* pull filtered pictures from the filtergraph */
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while (avfilter_poll_frame(buffersink_ctx->inputs[0])) {
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av_vsink_buffer_get_video_buffer_ref(buffersink_ctx, &picref, 0);
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if (picref) {
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display_picref(picref, buffersink_ctx->inputs[0]->time_base);
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avfilter_unref_buffer(picref);
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}
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}
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}
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}
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}
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end:
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avfilter_graph_free(&filter_graph);
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if (dec_ctx)
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avcodec_close(dec_ctx);
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av_close_input_file(fmt_ctx);
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if (ret < 0 && ret != AVERROR_EOF) {
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char buf[1024];
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av_strerror(ret, buf, sizeof(buf));
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fprintf(stderr, "Error occurred: %s\n", buf);
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exit(1);
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}
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exit(0);
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}
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