0,0 → 1,251 |
/* |
* Copyright (c) 2010 Nicolas George |
* Copyright (c) 2011 Stefano Sabatini |
* |
* Permission is hereby granted, free of charge, to any person obtaining a copy |
* of this software and associated documentation files (the "Software"), to deal |
* in the Software without restriction, including without limitation the rights |
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
* copies of the Software, and to permit persons to whom the Software is |
* furnished to do so, subject to the following conditions: |
* |
* The above copyright notice and this permission notice shall be included in |
* all copies or substantial portions of the Software. |
* |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
* THE SOFTWARE. |
*/ |
|
/** |
* @file |
* API example for decoding and filtering |
* @example doc/examples/filtering_video.c |
*/ |
|
#define _XOPEN_SOURCE 600 /* for usleep */ |
#include <unistd.h> |
|
#include <libavcodec/avcodec.h> |
#include <libavformat/avformat.h> |
#include <libavfilter/avfiltergraph.h> |
#include <libavfilter/avcodec.h> |
#include <libavfilter/buffersink.h> |
#include <libavfilter/buffersrc.h> |
|
const char *filter_descr = "scale=78:24"; |
|
static AVFormatContext *fmt_ctx; |
static AVCodecContext *dec_ctx; |
AVFilterContext *buffersink_ctx; |
AVFilterContext *buffersrc_ctx; |
AVFilterGraph *filter_graph; |
static int video_stream_index = -1; |
static int64_t last_pts = AV_NOPTS_VALUE; |
|
static int open_input_file(const char *filename) |
{ |
int ret; |
AVCodec *dec; |
|
if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n"); |
return ret; |
} |
|
if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n"); |
return ret; |
} |
|
/* select the video stream */ |
ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0); |
if (ret < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n"); |
return ret; |
} |
video_stream_index = ret; |
dec_ctx = fmt_ctx->streams[video_stream_index]->codec; |
|
/* init the video decoder */ |
if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n"); |
return ret; |
} |
|
return 0; |
} |
|
static int init_filters(const char *filters_descr) |
{ |
char args[512]; |
int ret; |
AVFilter *buffersrc = avfilter_get_by_name("buffer"); |
AVFilter *buffersink = avfilter_get_by_name("buffersink"); |
AVFilterInOut *outputs = avfilter_inout_alloc(); |
AVFilterInOut *inputs = avfilter_inout_alloc(); |
enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE }; |
AVBufferSinkParams *buffersink_params; |
|
filter_graph = avfilter_graph_alloc(); |
|
/* buffer video source: the decoded frames from the decoder will be inserted here. */ |
snprintf(args, sizeof(args), |
"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d", |
dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, |
dec_ctx->time_base.num, dec_ctx->time_base.den, |
dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den); |
|
ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", |
args, NULL, filter_graph); |
if (ret < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n"); |
return ret; |
} |
|
/* buffer video sink: to terminate the filter chain. */ |
buffersink_params = av_buffersink_params_alloc(); |
buffersink_params->pixel_fmts = pix_fmts; |
ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", |
NULL, buffersink_params, filter_graph); |
av_free(buffersink_params); |
if (ret < 0) { |
av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n"); |
return ret; |
} |
|
/* Endpoints for the filter graph. */ |
outputs->name = av_strdup("in"); |
outputs->filter_ctx = buffersrc_ctx; |
outputs->pad_idx = 0; |
outputs->next = NULL; |
|
inputs->name = av_strdup("out"); |
inputs->filter_ctx = buffersink_ctx; |
inputs->pad_idx = 0; |
inputs->next = NULL; |
|
if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr, |
&inputs, &outputs, NULL)) < 0) |
return ret; |
|
if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0) |
return ret; |
return 0; |
} |
|
static void display_frame(const AVFrame *frame, AVRational time_base) |
{ |
int x, y; |
uint8_t *p0, *p; |
int64_t delay; |
|
if (frame->pts != AV_NOPTS_VALUE) { |
if (last_pts != AV_NOPTS_VALUE) { |
/* sleep roughly the right amount of time; |
* usleep is in microseconds, just like AV_TIME_BASE. */ |
delay = av_rescale_q(frame->pts - last_pts, |
time_base, AV_TIME_BASE_Q); |
if (delay > 0 && delay < 1000000) |
usleep(delay); |
} |
last_pts = frame->pts; |
} |
|
/* Trivial ASCII grayscale display. */ |
p0 = frame->data[0]; |
puts("\033c"); |
for (y = 0; y < frame->height; y++) { |
p = p0; |
for (x = 0; x < frame->width; x++) |
putchar(" .-+#"[*(p++) / 52]); |
putchar('\n'); |
p0 += frame->linesize[0]; |
} |
fflush(stdout); |
} |
|
int main(int argc, char **argv) |
{ |
int ret; |
AVPacket packet; |
AVFrame *frame = av_frame_alloc(); |
AVFrame *filt_frame = av_frame_alloc(); |
int got_frame; |
|
if (!frame || !filt_frame) { |
perror("Could not allocate frame"); |
exit(1); |
} |
if (argc != 2) { |
fprintf(stderr, "Usage: %s file\n", argv[0]); |
exit(1); |
} |
|
avcodec_register_all(); |
av_register_all(); |
avfilter_register_all(); |
|
if ((ret = open_input_file(argv[1])) < 0) |
goto end; |
if ((ret = init_filters(filter_descr)) < 0) |
goto end; |
|
/* read all packets */ |
while (1) { |
if ((ret = av_read_frame(fmt_ctx, &packet)) < 0) |
break; |
|
if (packet.stream_index == video_stream_index) { |
avcodec_get_frame_defaults(frame); |
got_frame = 0; |
ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, &packet); |
if (ret < 0) { |
av_log(NULL, AV_LOG_ERROR, "Error decoding video\n"); |
break; |
} |
|
if (got_frame) { |
frame->pts = av_frame_get_best_effort_timestamp(frame); |
|
/* push the decoded frame into the filtergraph */ |
if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) { |
av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n"); |
break; |
} |
|
/* pull filtered frames from the filtergraph */ |
while (1) { |
ret = av_buffersink_get_frame(buffersink_ctx, filt_frame); |
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) |
break; |
if (ret < 0) |
goto end; |
display_frame(filt_frame, buffersink_ctx->inputs[0]->time_base); |
av_frame_unref(filt_frame); |
} |
} |
} |
av_free_packet(&packet); |
} |
end: |
avfilter_graph_free(&filter_graph); |
if (dec_ctx) |
avcodec_close(dec_ctx); |
avformat_close_input(&fmt_ctx); |
av_frame_free(&frame); |
av_frame_free(&filt_frame); |
|
if (ret < 0 && ret != AVERROR_EOF) { |
char buf[1024]; |
av_strerror(ret, buf, sizeof(buf)); |
fprintf(stderr, "Error occurred: %s\n", buf); |
exit(1); |
} |
|
exit(0); |
} |