ffmpeg编码转化

[无法支持的类型]

比如我接收手机传来的视频为h264编码格式的视频文件，很大，我想缩小它，码率调整一下，使用ffmpeg.exe直接用命令完全OK，可是用代码就会打不开报错
[libx264 @ 02a3e3a0] broken ffmpeg default settings detected
[libx264 @ 02a3e3a0] use an encoding preset (e.g. -vpre medium)
[libx264 @ 02a3e3a0] preset usage: -vpre <speed> -vpre <profile>
[libx264 @ 02a3e3a0] speed presets are listed in x264 --help
[libx264 @ 02a3e3a0] profile is optional; x264 defaults to high

怎么解决呢？

[无法支持的类型]

没有人来解答一下吗？还有编译ffmpeg 碰见 unkown option --enable-memalign-hack 是什么情况？我看很多人都说这个是windows编译ffmpeg的必选项啊

[zgl7903]

是不是路径问题？ 你是怎么代码写的？ 调用exe ?

[无法支持的类型]

引用 2 楼 zgl7903 的回复:

是不是路径问题？ 你是怎么代码写的？ 调用exe ?

调用exe是可以的，代码是雷神的代码，如下：

static int open_input_file(const char *filename)
{
	int ret;
	unsigned int i;
	ifmt_ctx = NULL;
	if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
		av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
		return ret;
	}
	if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
		av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
		return ret;
	}
	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
		AVStream *stream;
		AVCodecContext *codec_ctx;
		stream = ifmt_ctx->streams[i];
		codec_ctx = stream->codec;
		/* Reencode video & audio and remux subtitles etc. */
		if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
			|| codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
			/* Open decoder */
			ret = avcodec_open2(codec_ctx,
				avcodec_find_decoder(codec_ctx->codec_id), NULL);
			if (ret < 0) {
				av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
				return ret;
			}
		}
	}
	av_dump_format(ifmt_ctx, 0, filename, 0);
	return 0;
}
static int open_output_file(const char *filename)
{
	AVStream *out_stream;
	AVStream *in_stream;
	AVCodecContext *dec_ctx, *enc_ctx;
	AVCodec *encoder;
	int ret;
	unsigned int i;
	ofmt_ctx = NULL;
	avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
	if (!ofmt_ctx) {
		av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
		return AVERROR_UNKNOWN;
	}
	for (i = 0; i < ifmt_ctx->nb_streams; i++) 
	{
		out_stream = avformat_new_stream(ofmt_ctx, NULL);
		if (!out_stream)
		{
			av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
			return AVERROR_UNKNOWN;
		}
		in_stream = ifmt_ctx->streams[i];
		dec_ctx = in_stream->codec;
		enc_ctx = out_stream->codec;
		
		if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO|| dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) 
		{
		
			encoder = avcodec_find_encoder(dec_ctx->codec_id);     //在这里报错
			
			/* in this example, we choose transcoding to same codec */
			
			/* In this example, we transcode to same properties (picture size,
			 * sample rate etc.). These properties can be changed for output
			 * streams easily using filters */
			if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO)
			{
				enc_ctx->height = dec_ctx->height;
				enc_ctx->width = dec_ctx->width;
				enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
				/* take first format from list of supported formats */
				enc_ctx->pix_fmt = encoder->pix_fmts[0];
				/* video time_base can be set to whatever is handy and supported by encoder */
				enc_ctx->time_base = dec_ctx->time_base;
			}
			else
			{
				enc_ctx->sample_rate = dec_ctx->sample_rate;
				enc_ctx->channel_layout = dec_ctx->channel_layout;
				enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
				/* take first format from list of supported formats */
				enc_ctx->sample_fmt = encoder->sample_fmts[0];
				AVRational time_base = { 1, enc_ctx->sample_rate };
				enc_ctx->time_base = time_base;
			}
			
			/* Third parameter can be used to pass settings to encoder */
			ret = avcodec_open2(enc_ctx, encoder, NULL);
			if (ret < 0) 
			{
				av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
				return ret;
			}
		}
		else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN)
		{
			av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
			return AVERROR_INVALIDDATA;
		}
		else
		{
			/* if this stream must be remuxed */
			ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,ifmt_ctx->streams[i]->codec);
			if (ret < 0)
			{
				av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
				return ret;
			}
		}
		if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
	}
	av_dump_format(ofmt_ctx, 0, filename, 1);
	if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
	{
		ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
		if (ret < 0)
		{
			av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
			return ret;
		}
	}
	/* init muxer, write output file header */
	ret = avformat_write_header(ofmt_ctx, NULL);
	if (ret < 0)
	{
		av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
		return ret;
	}
	return 0;
}