由网友(一笑泯千愁)分享简介：我已检测功能 AV codec_de code_audio3 作品使用MP4格式慢，在这里我的code周期解码音频：I have detected that function avcodec_decode_audio3 works slow with mp4 format, here my code cycle fo...

我已检测功能 AV codec_de code_audio3 作品使用MP4格式慢，在这里我的code周期解码音频：

I have detected that function avcodec_decode_audio3 works slow with mp4 format, here my code cycle for decoding audio:

while (av_read_frame(av_format_context, &packet) >= 0 && is_play == 1) {
        if (av_codec_context->codec_type == AVMEDIA_TYPE_AUDIO
                && is_play == 1) {
            int out_size = AVCODEC_MAX_AUDIO_FRAME_SIZE;
            int size = packet.size;
            int n;
            int dataLength = size;
            int decoded = 0;
            while (size > 0) {

                //start measure time
                gettimeofday(&tvBegin, NULL);

                int len = avcodec_decode_audio3(av_codec_context,
                        (int16_t *) pAudioBuffer, &out_size, &packet);

                //stop measure time
                gettimeofday(&tvEnd, NULL);
                timeval_subtract(&tvDiff, &tvEnd, &tvBegin);

                LOGI("%d", tvDiff.tv_usec / 1000);
                LOGI("len='%d'", len);
                LOGI("out_size='%d'", out_size);

                if (len < 0) {
                    break;
                    return 1;
                }
                if (out_size > 0) {



                    jbyte *bytes = (*env)->GetByteArrayElements(env, array,
                            NULL);
                    memcpy(bytes, (int16_t *) pAudioBuffer, out_size);
                    (*env)->ReleaseByteArrayElements(env, array, bytes, 0);
                    (*env)->CallVoidMethod(env, obj, play, array, out_size,
                            is_play);

                }
                size -= len;
            }

        }
        if (packet.data)
            av_free_packet(&packet);

    }

但与其他格式，如FLAC和MP3，它工作正常。 AV codec_de code_audio3 采取解码MP3架约1-2 milisecounds与 out_size = 4608，但随着MP4的解码相同的帧大小大约需要6-7 millisecounds。我接到的这里。

But with other formats like flac and mp3 it works fine. avcodec_decode_audio3 take about 1-2 milisecounds for decoding mp3 frame with out_size = 4608 but with the same frame size in mp4 decoding take about 6-7 millisecounds. I got my build script from here.

它是否正常行为？什么办法可以提高解码MP4的表现呢？

Does it normal behavior? Is any way to increase performance of decoding mp4?

推荐答案

ü可以硬件加速搜索...

u could search on hardware acceleration...

H / W加速H.264解码Android上的

"H/W Accelerated H.264 Decoding on Android"

例如：

How在Android上使用硬件加速的视频解码？

http://readlist.com/lists/mplayerhq。胡/ mplayer的用户/ 5 / 26751.html

IMO - ffmpeg的仍主要集中在软件，但在Android的新版本，你可以找到一些stagefright的API提供GPU加速的方式来访问帧缓冲??

IMO - ffmpeg is still mostly in software but on the newer versions of android, you may be able to find some stagefright API's providing GPU accelerated way to access the framebuffer??