Android如何增加ffmpeg mp4 perfromance？ [英] Android how to increase ffmpeg mp4 perfromance?

问题描述

我检测到功能 avcodec_decode_audio3 使用mp4格式工作缓慢，这里我的代码循环解码音频：

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，它的工作正常。 avcodec_decode_audio3 需要大约1-2毫秒来解码mp3帧与 out_size = 4608，但在mp4解码中具有相同的帧大小花费约6-7毫秒。我从此处获取我的构建脚本。

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.

是否正常行为？是否有任何方法提高解码mp4的性能？

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

推荐答案

你可以搜索硬件加速...

u could search on hardware acceleration...

H / W加速H.264解码在Android上

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

例如：

如何在Android上使用硬件加速视频解码？

http://readlist.com/lists/mplayerhq.hu/mplayer-users/5/26751.html

IMO - ffmpeg仍然主要是软件，但在较新版本的Android，您可能可以找到一些stagefright API提供GPU加速方式来访问framebuffer？

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??

这篇关于Android如何增加ffmpeg mp4 perfromance？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！