所有
我在win7中使用FFmpeg.AutoGen 3.2，vs2015，从FFmpeg（http://ffmpeg.org/doxygen/trunk/filtering_video_8c-example.html）复制一个示例，
运行时
string video = @"e:\\1.avi";
FilterVideo fv = new FilterVideo();
fv.filtertest(video);
返回错误代码-22： ARGS：video_size = 640×480：pix_fmt = AV_PIX_FMT_YUV420P：那么time_base = 1/25：pixel_aspect = 1/1的 无法创建缓冲源 -22
感谢任何代表。
打击代码：
using FFmpeg.AutoGen;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace videoFFmpegAutoGen.tool
{
public unsafe class FilterVideo
{
public int open_input_file(string filename)
{
try
{
int ret;
AVCodec* dec;
fixed (AVFormatContext** at = &fmt_ctx)
{
ret = ffmpeg.avformat_open_input(at, filename, null, null);
}
if (ret < 0)
{
Console.WriteLine("Cannot open input file\n");
return ret;
}
ret = ffmpeg.avformat_find_stream_info(fmt_ctx, null);
if (ret < 0)
{
Console.WriteLine("Cannot find stream information\n");
return ret;
}
ret = ffmpeg.av_find_best_stream(fmt_ctx, AVMediaType.AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0);
if (ret < 0)
{
Console.WriteLine("Cannot find a video stream in the input file\n");
return ret;
}
video_stream_index = ret;
/* create decoding context */
dec_ctx = ffmpeg.avcodec_alloc_context3(dec);
ffmpeg.avcodec_parameters_to_context(dec_ctx, fmt_ctx->streams[video_stream_index]->codecpar);
ffmpeg.av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0);
/* init the video decoder */
if ((ret = ffmpeg.avcodec_open2(dec_ctx, dec, null)) < 0)
{
Console.WriteLine("Cannot open video decoder\n");
return ret;
}
return ret;
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
finally
{
}
return -1;
}
private string filters_descr = "scale=78:24,transpose=cclock";
private int video_stream_index = -1;
private AVFormatContext* fmt_ctx;
private AVFilterGraph* filter_graph;
AVFilterContext* buffersrc_ctx;
private AVCodecContext* dec_ctx;
AVFilterContext* buffersink_ctx;
public unsafe int init_filters(string filters_descr)
{
int ret = 0;
AVFilterInOut* outputs = null;
AVFilterInOut* inputs = null;
try
{
AVFilter* buffersrc = ffmpeg.avfilter_get_by_name("buffer");
AVFilter* buffersink = ffmpeg.avfilter_get_by_name("buffersink");
outputs = ffmpeg.avfilter_inout_alloc();
inputs = ffmpeg.avfilter_inout_alloc();
AVRational time_base = fmt_ctx->streams[video_stream_index]->time_base;
filter_graph = ffmpeg.avfilter_graph_alloc();
//string args = string.Format("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, time_base.num, time_base.den, dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
string args = string.Format("video_size={0}x{1}:pix_fmt={2}:time_base={3}/{4}:pixel_aspect={5}/{6}", dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, time_base.num, time_base.den, dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
// string args = string.Format("video_size={0}x{1}:time_base={2}/{3}:pixel_aspect={4}/{5}", dec_ctx->width, dec_ctx->height, time_base.num, time_base.den, dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
// string args = string.Format("video_size={0}x{1}", dec_ctx->width, dec_ctx->height);
Console.WriteLine("args:" + args);
fixed (AVFilterContext** at= &buffersrc_ctx)
{
ret = ffmpeg.avfilter_graph_create_filter(at, buffersrc, "in", args, null, filter_graph);
}
if (ret < 0)
{
Console.WriteLine("Cannot create buffer source\n"+ret);
return ret;
}
fixed (AVFilterContext** at = &buffersink_ctx)
{
ret = ffmpeg.avfilter_graph_create_filter(at, buffersink, "out", null, null, filter_graph);
}
if (ret < 0)
{
Console.WriteLine("Cannot create buffer sink\n");
return ret;
}
// ret = ffmpeg.av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts,AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
/*
* The buffer source output must be connected to the input pad of
* the first filter described by filters_descr; since the first
* filter input label is not specified, it is set to "in" by
* default.
*/
outputs->name = ffmpeg.av_strdup("in");
outputs->filter_ctx = buffersrc_ctx;
outputs->pad_idx = 0;
outputs->next = null;
/*
* The buffer sink input must be connected to the output pad of
* the last filter described by filters_descr; since the last
* filter output label is not specified, it is set to "out" by
* default.
*/
inputs->name = ffmpeg.av_strdup("out");
inputs->filter_ctx = buffersink_ctx;
inputs->pad_idx = 0;
inputs->next = null;
ret = ffmpeg.avfilter_graph_parse_ptr(filter_graph, filters_descr, &inputs, &outputs, null);
if (ret < 0)
{
return ret;
}
ret = ffmpeg.avfilter_graph_config(filter_graph, null);
if (ret < 0)
{
return ret;
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
finally
{
ffmpeg.avfilter_inout_free(&inputs);
ffmpeg.avfilter_inout_free(&outputs);
}
return ret;
}
long AV_NOPTS_VALUE = 1;
//int last_pts = AV_NOPTS_VALUE;
long last_pts = 1;
public void display_frame(AVFrame* frame, AVRational time_base)
{
int x, y;
long delay;
sbyte* p0;
sbyte* p;
AVRational cq = new AVRational();
cq.num = 1;
cq.den = 1000000;
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 = ffmpeg.av_rescale_q(frame->pts - last_pts, time_base, cq);
if (delay > 0 && delay < 1000000)
Thread.Sleep((int)delay);
}
last_pts = frame->pts;
}
/* Trivial ASCII grayscale display. */
p0 = frame->data0;
//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);
}
private int AV_BUFFERSRC_FLAG_KEEP_REF = 8 ;
public unsafe void filtertest(string inputvideo)
{
AVFrame* frame = ffmpeg.av_frame_alloc();
AVFrame* filt_frame = ffmpeg.av_frame_alloc();
try
{
int ret;
AVPacket packet;
ffmpeg.av_register_all();
ffmpeg.avfilter_register_all();
ret = open_input_file(inputvideo);
if (ret < 0)
{
return;
}
ret = init_filters(filters_descr);
if (ret < 0)
{
return;
}
while (true)
{
ret = ffmpeg.av_read_frame(fmt_ctx, &packet);
if (ret < 0)
{
Console.WriteLine("Error while sending a packet to the decoder\n");
break;
}
if (packet.stream_index == video_stream_index)
{
ret = ffmpeg.avcodec_send_packet(dec_ctx, &packet);
if (ret < 0)
{
Console.WriteLine( "Error while sending a packet to the decoder\n");
break;
}
while (ret >= 0)
{
ret = ffmpeg.avcodec_receive_frame(dec_ctx, frame);
//if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
if (ret == 999)
{
break;
}
else if (ret < 0)
{
Console.WriteLine("Error while receiving a frame from the decoder\n");
return;
} else
{
Console.WriteLine("ret::"+ret);
}
if (ret >= 0)
{
frame->pts = frame->best_effort_timestamp;
/* push the decoded frame into the filtergraph */
if (ffmpeg.av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0)
{
Console.WriteLine("Error while feeding the filtergraph\n");
break;
}
/* pull filtered frames from the filtergraph */
while (true)
{
ret = ffmpeg.av_buffersink_get_frame(buffersink_ctx, filt_frame);
//if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
if (ret == 999)
{
break;
}
else if (ret < 0)
{
return;
}else
{
Console.WriteLine("ret2:" + ret);
}
display_frame(filt_frame, buffersink_ctx->inputs[0]->time_base);
ffmpeg.av_frame_unref(filt_frame);
}
ffmpeg.av_frame_unref(frame);
}
}
}
ffmpeg.av_packet_unref(&packet);
}
}
catch(Exception e)
{
Console.WriteLine(e.ToString());
}
finally
{
fixed (AVFilterGraph** at = &filter_graph)
{
ffmpeg.avfilter_graph_free(at);
}
ffmpeg.avcodec_close(dec_ctx);
fixed (AVFormatContext** at = &fmt_ctx)
{
ffmpeg.avformat_close_input(at);
}
ffmpeg.av_frame_free(&frame);
ffmpeg.av_frame_free(&filt_frame);
}
}
}
}
答案 0 :(得分：0)
我敢打赌问题出在这一行：
string args = string.Format("video_size={0}x{1}:pix_fmt={2}:time_base={3}/{4}:pixel_aspect={5}/{6}", dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, time_base.num, time_base.den, dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
pix_fmt肯定是int，而不是作为字符串传递。
所以得到dec_ctx->pix_fmt的整数值，它应该可以工作。