Add Watermark on Video with OpenCV and FFmpeg¶
之前写过一篇use opencv to add watermark in a video，但是发现有个问题：
- 处理后的视频无法保留原来视频中的音频信息
所以决定再探究一下。
经过调查发现FFmpeg应用相当广泛，几乎是音视频领域的瑞士军刀，所以我也试一下水，经过三个星期的摸索，终于初步解决了上面提到的那个问题。觉得相当的欣慰，对自己感到非常满意 ;-)
程序的主要功能是，读入一个视频(其中包含音频)，给视频图像左上角添加一个黄色方块后，输出成相同格式的视频文件，并保留原文件中的音频信息。
代码文件: ffmpeg-opencv-transcode.cpp
源代码¶
/**
* Copyright (c) 2010 Nicolas George
* Copyright (c) 2011 Stefano Sabatini
* Copyright (c) 2014 Andrey Utkin
* Copyright (c) 2016 Wang Zhizhou email: 824219521@qq.com
* modified from ffmpeg offical example named: transcoding.c
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfiltergraph.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/opt.h>
#include <libavutil/pixdesc.h>
#include <libswscale/swscale.h>
}
static AVFormatContext *ifmt_ctx;
static AVFormatContext *ofmt_ctx;
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) {
/* 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) {
/* in this example, we choose transcoding to same codec */
encoder = avcodec_find_encoder(dec_ctx->codec_id);
if (!encoder) {
av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
return AVERROR_INVALIDDATA;
}
/* 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 (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
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 */
if (encoder->pix_fmts)
enc_ctx->pix_fmt = encoder->pix_fmts[0];
else
enc_ctx->pix_fmt = dec_ctx->pix_fmt;
/* video time_base can be set to whatever is handy and supported by encoder */
enc_ctx->time_base = dec_ctx->time_base;
out_stream->time_base = enc_ctx->time_base;
if(dec_ctx->codec_id == AV_CODEC_ID_H264)
{
enc_ctx->me_range = 16;
enc_ctx->max_qdiff = 4;
enc_ctx->qmin = 11;
enc_ctx->qmax =30;
enc_ctx->qcompress = 0.7;
}
/* 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(AVMEDIA_TYPE_AUDIO == ofmt_ctx->streams[i]->codec->codec_type)
{
ofmt_ctx->streams[i]->codec->codec_tag = 0;
}
if (ret < 0) {
av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
return ret;
}
}
}
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;
}
static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, int *got_frame) {
int ret;
int got_frame_local;
AVPacket enc_pkt;
if (!got_frame)
got_frame = &got_frame_local;
av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
/* encode filtered frame */
enc_pkt.data = NULL;
enc_pkt.size = 0;
av_init_packet(&enc_pkt);
ret = avcodec_encode_video2(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
filt_frame, got_frame);
av_frame_free(&filt_frame);
if (ret < 0)
return ret;
if (!(*got_frame))
return 0;
/* prepare packet for muxing */
enc_pkt.stream_index = stream_index;
av_packet_rescale_ts(&enc_pkt,
ofmt_ctx->streams[stream_index]->codec->time_base,
ofmt_ctx->streams[stream_index]->time_base);
av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
/* mux encoded frame */
ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
return ret;
}
static int flush_encoder(unsigned int stream_index){
int ret;
int got_frame;
if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
AV_CODEC_CAP_DELAY))
return 0;
while (1) {
av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
ret = encode_write_frame(NULL, stream_index, &got_frame);
if (ret < 0)
break;
if (!got_frame)
return 0;
}
return ret;
}
//#define USE_OPENCV //注释这一句后运行，对应不加水印的输出视频
#ifdef USE_OPENCV
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;
/** 这个函数里使用OpenCV处理图像 **/
void addWaterMarkOnTheImage(Mat &imageFrame)
{
Mat waterMark = Mat(100,100,CV_8UC3,Scalar(0,255,255)); //模拟水印图像
Mat imageROI = imageFrame(Rect(10,10,waterMark.cols,waterMark.rows));
cv::addWeighted(imageROI, 0, waterMark, 1, 0, imageROI); //添加水印到视频图像帧上
}
/** ------ **/
AVFrame* useOpenCVProcessFrame(AVFrame *frame, int stream_index)
{
AVStream *in_stream = ifmt_ctx->streams[stream_index];
AVCodecContext *pCodecCtx = in_stream->codec;
AVFrame *pFrameRGB = NULL;
/* 源图像格式向BGR24转换 */
struct SwsContext * img_convert_ctx = NULL;
if(img_convert_ctx == NULL){
img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
AV_PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL);
}
pFrameRGB = av_frame_alloc();
int size = avpicture_get_size(AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
uint8_t *out_bufferRGB = new uint8_t[size];
avpicture_fill((AVPicture *)pFrameRGB, out_bufferRGB, AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
sws_scale(img_convert_ctx, frame->data, frame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
Mat imageFrame = Mat(pCodecCtx->height, pCodecCtx->width, CV_8UC3);
memcpy(imageFrame.data, out_bufferRGB, size);
delete[] out_bufferRGB;
/*** 源图像格式向BGR24转换结束 ***/
addWaterMarkOnTheImage(imageFrame);//使用OpenCV向图像添加水印
imshow("image",imageFrame);
waitKey(1);
//OpenCV Mat图像数据转为FFmpeg AVFrame图像帧数据
avpicture_fill((AVPicture *)pFrameRGB, imageFrame.data,AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
/* BGR24向源图像格式转换 */
struct SwsContext * convert_ctx = NULL;
if(convert_ctx == NULL){
convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
AV_PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height,
pCodecCtx->pix_fmt, SWS_BICUBIC, NULL, NULL, NULL);
}
AVFrame *srcFrame = av_frame_alloc();
size = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
uint8_t *out_buffer = new uint8_t[size];
avpicture_fill((AVPicture *)srcFrame, out_buffer, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
sws_scale(convert_ctx, pFrameRGB->data, pFrameRGB->linesize, 0, pCodecCtx->height, srcFrame->data, srcFrame->linesize);
delete[] out_buffer;
/*** BGR24向源图像格式转换结束 ***/
av_free(pFrameRGB);
srcFrame->width = frame->width;
srcFrame->height = frame->height;
srcFrame->format = frame->format;
av_frame_copy_props(srcFrame, frame);
return srcFrame;
}
#endif
int main(int argc, char **argv){
int ret;
AVPacket packet = { .data = NULL, .size = 0 };
AVFrame *frame = NULL;
enum AVMediaType type;
unsigned int stream_index;
unsigned int i;
int got_frame;
if (argc != 3) {
av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
return 1;
}
av_register_all();
avfilter_register_all();
if ((ret = open_input_file(argv[1])) < 0)
goto end;
if ((ret = open_output_file(argv[2])) < 0)
goto end;
/* read all packets */
while (1) {
if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
break;
stream_index = packet.stream_index;
type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
stream_index);
if (type == AVMEDIA_TYPE_VIDEO) {
av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
frame = av_frame_alloc();
if (!frame) {
ret = AVERROR(ENOMEM);
break;
}
av_packet_rescale_ts(&packet,
ifmt_ctx->streams[stream_index]->time_base,
ifmt_ctx->streams[stream_index]->codec->time_base);
ret = avcodec_decode_video2(ifmt_ctx->streams[stream_index]->codec, frame,
&got_frame, &packet);
if (ret < 0) {
av_frame_free(&frame);
av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
break;
}
if (got_frame) {
#ifdef USE_OPENCV
AVFrame *convertFrame = useOpenCVProcessFrame(frame,stream_index);
convertFrame->pts = av_frame_get_best_effort_timestamp(frame);
convertFrame->pict_type = AV_PICTURE_TYPE_NONE;
ret = encode_write_frame(convertFrame, stream_index, NULL);
#else
frame->pts = av_frame_get_best_effort_timestamp(frame);
frame->pict_type = AV_PICTURE_TYPE_NONE;
ret = encode_write_frame(frame, stream_index, NULL);
#endif
if (ret < 0)
goto end;
} else {
av_frame_free(&frame);
}
} else {
/* remux this frame without reencoding */
av_packet_rescale_ts(&packet,
ifmt_ctx->streams[stream_index]->time_base,
ofmt_ctx->streams[stream_index]->time_base);
ret = av_interleaved_write_frame(ofmt_ctx, &packet);
if (ret < 0)
goto end;
}
av_packet_unref(&packet);
}
/* flush filters and encoders */
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
/* flush encoder */
if(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
{
ret = flush_encoder(i);
if (ret < 0) {
av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
goto end;
}
}
}
av_write_trailer(ofmt_ctx);
end:
av_packet_unref(&packet);
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
avcodec_close(ifmt_ctx->streams[i]->codec);
if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
avcodec_close(ofmt_ctx->streams[i]->codec);
}
avformat_close_input(&ifmt_ctx);
if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
avio_closep(&ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
if (ret < 0)
av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
return ret ? 1 : 0;
}
本程序运行调用了ffmpeg-2.8.6和opencv-3.0.1版的库(库的安装读者还是自己搞定吧，有事联系: 824219521@qq.com)
编译¶
使用g++编译，编译命令如下：
g++ ffmpeg-opencv-transcode.cpp -I/usr/local/include -L/usr/local/lib -lavcodec -lavformat -lswscale -lavfilter -lavutil -lx264 -lz -lm -lopencv_imgproc -lopencv_highgui -lopencv_core
使用¶
使用方法：
./a.out input.mp4 output.mp4
测试视频¶
这里有几个测试视频可供使用：