［ffmpeg求助］调用avio_alloc_context()自定义write_packet发生内存泄漏

[sunhygwjl]

劳烦各位大神帮忙看一下下面的代码有什么问题？为什么进程在运行过程中（即while(1)循环中）占用内存一直在不断增加？最终导致系统内存耗尽，无法申请新的内存。是AVIOContext结构的初始化有问题？还是哪里有问题？看了很久也没有找到原因。打印调试发现内存即将耗尽时，进程会阻塞在av_interleaved_write_frame()，最终返回错误推出循环。所以，应该是在该函数中不断申请内存又没有释放，但具体不知道是哪里申请了内存。希望大家能指点一二，感激不尽！！！

int fp_write = -1;

int write_packet(void *opaque, uint8_t *buff, int buf_size)
{
    int sentbyte = -1;
	if (fp_write != -1)
	{
		sentbyte = write(fp_write, buff, buf_size);
	}
	
    return sentbyte;
}

int main(void)
{
	int ret = 0, i;
    AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
	AVIOContext *avio_out = NULL;
    AVPacket pkt;
#define USE_H264BSF
#ifdef USE_H264BSF
	AVBitStreamFilterContext *h264bsfc = NULL;
    int video_index = -1;
#endif
    char *in_filename, *out_filename;
	unsigned char *out_buff = NULL;

    in_filename  = "/tmp/media/mp4.mp4";
    out_filename = "/tmp/media/test_video.ts";

    av_register_all();

    if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0)
    {
        fprintf(stderr, "Could not open input file '%s'", in_filename);
        goto end;
    }

    if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0)
    {
        fprintf(stderr, "Failed to retrieve input stream information");
        goto end;
    }

	/* Allocate buffer for output data */
	out_buff = (unsigned char *)av_malloc(OUT_BUFF_LEN);
	printf("out_buff: 0x%p\n", out_buff);
	if (!out_buff)
	{
		fprintf(stderr, "av_malloc error\n");
		goto end;
	}

	/* Output file for testing */
	fp_write = open(out_filename, O_WRONLY | O_CREAT);
	if (fp_write == -1)
	{
		perror("open");
		goto end;
	}
	
	/* Allocate avformat */
	ofmt_ctx = avformat_alloc_context();
    if (!ofmt_ctx)
    {
        fprintf(stderr, "Could not create output context\n");
        ret = AVERROR_UNKNOWN;
        goto end;
    }
	ofmt_ctx->oformat = av_guess_format("mpegts", NULL, NULL);
	if (!ofmt_ctx->oformat)
	{
		fprintf(stderr, "Could not set output format\n");
        ret = AVERROR_UNKNOWN;
        goto end;
	}
	
    /* Allocate avio context */
	avio_out = avio_alloc_context(out_buff, OUT_BUFF_LEN, 1, NULL, NULL, write_packet, NULL);
	if (!avio_out)
	{
		fprintf(stderr, "Could not create avio context\n");
        ret = AVERROR_UNKNOWN;
        goto end;
	}
		
	/* AVIO struct */
	ofmt_ctx->pb = avio_out; 
	ofmt_ctx->flags = AVFMT_FLAG_CUSTOM_IO;

    for (i = 0; i < ifmt_ctx->nb_streams; i++)
    {
        AVStream *in_stream = ifmt_ctx->streams[i];
        AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
        if (!out_stream) {
            fprintf(stderr, "Failed allocating output stream\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
        if (ret < 0) {
            fprintf(stderr, "Failed to copy context from input to output stream codec context\n");
            goto end;
        }
        out_stream->codec->codec_tag = 0;
        if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
        {
			out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
		}
#ifdef USE_H264BSF
		/* mark video index */
		if (out_stream->codec->codec_type == AVMEDIA_TYPE_VIDEO)
		{
			video_index = i;
		}
#endif
    }

    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0)
    {
        fprintf(stderr, "Error occurred when opening output file\n");
        goto end;
    }

#ifdef USE_H264BSF
	h264bsfc = av_bitstream_filter_init("h264_mp4toannexb");
#endif
    while (1) {
        AVStream *in_stream, *out_stream;
        ret = av_read_frame(ifmt_ctx, &pkt);
        if (ret < 0)
        {
        	av_packet_unref(&pkt);
			break;
		}
#ifdef USE_H264BSF
		if (pkt.stream_index == video_index)
		{
			av_bitstream_filter_filter(h264bsfc, ifmt_ctx->streams[video_index]->codec,
				NULL, &pkt.data, &pkt.size, pkt.data, pkt.size, 0);
		}
#endif
        in_stream  = ifmt_ctx->streams[pkt.stream_index];
        out_stream = ofmt_ctx->streams[pkt.stream_index];

        /* copy packet */
        pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
        pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
        pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
        pkt.pos = -1;

        ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
		if (ret < 0) {
            fprintf(stderr, "Error muxing packet\n");
			av_packet_unref(&pkt);
            break;
        }
		
		av_packet_unref(&pkt);
    }

    av_write_trailer(ofmt_ctx);
    
end:
    avformat_close_input(&ifmt_ctx);

    /* close output */
	if (!avio_out && out_buff)
	{
		av_freep(&out_buff);
	}
	
    if (avio_out)
    {
		av_freep(&avio_out->buffer);
		av_freep(&avio_out);
		
	}
    
	if (fp_write != -1)
	{
		close(fp_write);
	}
	
	avformat_free_context(ofmt_ctx);

#ifdef USE_H264BSF
	av_bitstream_filter_close(h264bsfc);
#endif	

    if (ret < 0 && ret != AVERROR_EOF)
    {
        fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
        return 1;
    }

	return 0;
}

[rightorwrong]

看看demo程序对那几个结构体怎么释放的

[qige26]

顶起，我也遇到相同问题

[fangshy]

楼主解决了 分享下思路，我也遇到了

[百灵工作室]

pkt定义为指针AVPacket*试试

[CyberLogix]

估计是那块vbuffer没有释放导致， av_packet_unref(&pkt); out_buff = (unsigned char *)av_malloc(OUT_BUFF_LEN); /* Allocate avio context */ avio_out = avio_alloc_context(out_buff, OUT_BUFF_LEN, 1, NULL, NULL, write_packet, NULL);

[sunhygwjl]

最后没有做下去了。。。

[XP_online]

av_packet_unref只是给avpacket重新置空，并不会析构avpacket中data的内存。要不自己析构，要不调用av_free_packet去析构。