主要用到的api
avfilter_register_all()：注册所有AVFilter。
avfilter_graph_alloc()：为FilterGraph分配内存。
avfilter_graph_create_filter()：创建并向FilterGraph中添加一个Filter。
avfilter_graph_parse_ptr()：将一串通过字符串描述的Graph添加到FilterGraph中。
avfilter_graph_config()：检查FilterGraph的配置。
av_buffersrc_add_frame()：向FilterGraph中加入一个AVFrame。
av_buffersink_get_frame()：从FilterGraph中取出一个AVFrame。
源代码：
#include <jni.h>
#include <android/log.h>
#include <android/native_window.h>
#include <android/native_window_jni.h>
extern "C" {
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "libavutil/imgutils.h"
//-----AVfilter-----
#include <libavfilter/avfiltergraph.h>
#include <libavfilter/buffersrc.h>
#include <libavfilter/buffersink.h>
//-----AVfilter-----
};
#define LOG_TAG "JNI_TAG"
#define LOGD(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
const char *filters_descr = "lutyuv='u=128:v=128'";
//const char *filters_descr = "hflip";
//const char *filters_descr = "hue='h=60:s=-3'";
//const char *filters_descr = "crop=2/3*in_w:2/3*in_h";
//const char *filters_descr = "drawbox=x=200:y=200:w=300:h=300:color=pink@0.5";
//const char *filters_descr = "movie=/storage/emulated/0/shuiyin.png[wm];[in][wm]overlay=5:5[out]";
//const char *filters_descr="drawgrid=width=100:height=100:thickness=4:color=pink@0.9";
int getCodecContext(AVCodecParameters *codecpar, AVCodecContext **avCodecContext) {
AVCodec *dec = avcodec_find_decoder(codecpar->codec_id);
if (!dec) {
LOGD("can not find decoder");
return -1;
}
*avCodecContext = avcodec_alloc_context3(dec);
if (!*avCodecContext) {
LOGD("can not alloc new decodecctx");
return -1;
}
if (avcodec_parameters_to_context(*avCodecContext, codecpar) < 0) {
avcodec_free_context(avCodecContext);
*avCodecContext = NULL;
LOGD("can not fill decodecctx");
return -1;
}
if (avcodec_open2(*avCodecContext, dec, 0) != 0) {
LOGD("cant not open audio strames");
avcodec_free_context(avCodecContext);
*avCodecContext = NULL;
return -1;
}
return 0;
}
extern "C"
JNIEXPORT void JNICALL
Java_com_zzw_ffmpegdemo_FFmpegHelper_play(JNIEnv *env, jobject instance, jstring url_,
jobject surface) {
const char *url = env->GetStringUTFChars(url_, 0);
AVFormatContext *pFormatCtx = NULL;
AVCodecContext *pCodecCtx = NULL;
AVFilterContext *buffersink_ctx = NULL;
AVFilterContext *buffersrc_ctx = NULL;
AVFilterGraph *filter_graph = NULL;
//-----------------------------AVCodecContext init start----------------------------
av_register_all();
avfilter_register_all();//
pFormatCtx = avformat_alloc_context();
// Open video file
if (avformat_open_input(&pFormatCtx, url, NULL, NULL) != 0) {
LOGD("Couldn't open url:%s\n", url);
return; // Couldn't open file
}
// Retrieve stream information
if (avformat_find_stream_info(pFormatCtx, NULL) < 0) {
LOGD("Couldn't find stream information.");
return;
}
// Find the first video stream
int videoStream = -1, i;
for (i = 0; i < pFormatCtx->nb_streams; i++) {
if (pFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO
&& videoStream < 0) {
videoStream = i;
}
}
if (videoStream == -1) {
LOGD("Didn't find a video stream.");
return; // Didn't find a video stream
}
if (getCodecContext(pFormatCtx->streams[videoStream]->codecpar, &pCodecCtx) != 0) {
LOGD("Didn't get CodecContext.");
return;
}
//-----------------------------AVCodecContext init end-------------------------------
//------------------------------filter init start------------------------------------
char args[512];
AVFilter *buffersrc = avfilter_get_by_name("buffer");
AVFilter *buffersink = avfilter_get_by_name("buffersink");//新版的ffmpeg库必须为buffersink
AVFilterInOut *outputs = avfilter_inout_alloc();
AVFilterInOut *inputs = avfilter_inout_alloc();
enum AVPixelFormat pix_fmts[] = {AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE};
filter_graph = avfilter_graph_alloc();
/* buffer video source: the decoded frames from the decoder will be inserted here. */
snprintf(args, sizeof(args),
"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
pFormatCtx->streams[videoStream]->time_base.num,
pFormatCtx->streams[videoStream]->time_base.den,
pCodecCtx->sample_aspect_ratio.num, pCodecCtx->sample_aspect_ratio.den);
if (avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
args, NULL, filter_graph) < 0) {
LOGD("Cannot create buffer source\n");
return;
}
AVBufferSinkParams *buffersink_params = av_buffersink_params_alloc();
buffersink_params->pixel_fmts = pix_fmts;
if (avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
NULL, buffersink_params, filter_graph) < 0) {
LOGD("Cannot create buffer sink\n");
return;
}
av_free(buffersink_params);
/* Endpoints for the filter graph. */
outputs->name = av_strdup("in");
outputs->filter_ctx = buffersrc_ctx;
outputs->pad_idx = 0;
outputs->next = NULL;
inputs->name = av_strdup("out");
inputs->filter_ctx = buffersink_ctx;
inputs->pad_idx = 0;
inputs->next = NULL;
if ((avfilter_graph_parse_ptr(filter_graph, filters_descr,
&inputs, &outputs, NULL)) < 0) {
LOGD("Cannot avfilter_graph_parse_ptr\n");
return;
}
if ((avfilter_graph_config(filter_graph, NULL)) < 0) {
LOGD("Cannot avfilter_graph_config\n");
return;
}
//------------------------------filter init end------------------------------------
//------------------------------window init start-----------------------------------
// 获取native window
ANativeWindow *nativeWindow = ANativeWindow_fromSurface(env, surface);
// 获取视频宽高
int videoWidth = pCodecCtx->width;
int videoHeight = pCodecCtx->height;
// 设置native window的buffer大小,可自动拉伸
ANativeWindow_setBuffersGeometry(nativeWindow, videoWidth, videoHeight,
WINDOW_FORMAT_RGBA_8888);
ANativeWindow_Buffer windowBuffer;
//------------------------------window init end-----------------------------------
//------------------------------get data-----------------------------------
// 用于渲染
AVFrame *pFrameRGBA = av_frame_alloc();
// Determine required buffer size and allocate buffer
// buffer中数据就是用于渲染的,且格式为RGBA
int numBytes = av_image_get_buffer_size(AV_PIX_FMT_RGBA, pCodecCtx->width, pCodecCtx->height,
1);
uint8_t *buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
av_image_fill_arrays(pFrameRGBA->data, pFrameRGBA->linesize, buffer, AV_PIX_FMT_RGBA,
pCodecCtx->width, pCodecCtx->height, 1);
// 由于解码出来的帧格式不是RGBA的,在渲染之前需要进行格式转换
SwsContext *sws_ctx = sws_getContext(pCodecCtx->width,
pCodecCtx->height,
pCodecCtx->pix_fmt,
pCodecCtx->width,
pCodecCtx->height,
AV_PIX_FMT_RGBA,
SWS_BILINEAR,
NULL,
NULL,
NULL);
AVPacket *packet = av_packet_alloc();
int count = 0;
while (av_read_frame(pFormatCtx, packet) == 0) {
// Is this a packet from the video stream?
if (packet->stream_index == videoStream) {
// Decode video frame
if (avcodec_send_packet(pCodecCtx, packet) != 0) {
break;
}
AVFrame *pFrame = av_frame_alloc();
while (avcodec_receive_frame(pCodecCtx, pFrame) == 0) {
// lock native window buffer
ANativeWindow_lock(nativeWindow, &windowBuffer, 0);
//for AVfilter start
pFrame->pts = av_frame_get_best_effort_timestamp(pFrame);
//* push the decoded frame into the filtergraph
if (av_buffersrc_add_frame(buffersrc_ctx, pFrame) == 0) {
av_buffersink_get_frame(buffersink_ctx, pFrame);
} else{
LOGD("Could not av_buffersrc_add_frame");
}
// 格式转换
sws_scale(sws_ctx, (uint8_t const *const *) pFrame->data,
pFrame->linesize, 0, pCodecCtx->height,
pFrameRGBA->data, pFrameRGBA->linesize);
// 获取stride
uint8_t *dst = (uint8_t *) windowBuffer.bits;
int dstStride = windowBuffer.stride * 4;
uint8_t *src = (pFrameRGBA->data[0]);
int srcStride = pFrameRGBA->linesize[0];
// 由于window的stride和帧的stride不同,因此需要逐行复制
int h;
for (h = 0; h < videoHeight; h++) {
memcpy(dst + h * dstStride, src + h * srcStride, srcStride);
}
ANativeWindow_unlockAndPost(nativeWindow);
count++;
LOGD("解码渲染%d帧", count);
}
av_frame_free(&pFrame);
av_free(pFrame);
}
}
ANativeWindow_release(nativeWindow);
av_packet_free(&packet);
sws_freeContext(sws_ctx);
avfilter_inout_free(&outputs);
av_free(outputs);
avfilter_inout_free(&inputs);
av_free(inputs);
av_free(buffer);
av_frame_free(&pFrameRGBA);
av_free(pFrameRGBA);
avfilter_graph_free(&filter_graph); //for avfilter
// Close the codecs
avcodec_close(pCodecCtx);
avcodec_free_context(&pCodecCtx);
pCodecCtx = NULL;
// Close the video file
avformat_close_input(&pFormatCtx);
avformat_free_context(pFormatCtx);
pFormatCtx = NULL;
env->ReleaseStringUTFChars(url_, url);
}
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