利用FFmpeg对RGB图像进行H264编码

代码摘自：https://stackoverflow.com/questions/2940671/how-does-one-encode-a-series-of-images-into-h264-using-the-x264-c-api

extern "C"{#include <libavcodec/avcodec.h>#include <libavutil/imgutils.h>#include <libavutil/opt.h>#include <libswscale/swscale.h>}static AVCodecContext *c = NULL;static AVFrame *frame;static AVPacket pkt;static FILE *file;struct SwsContext *sws_context = NULL;static void ffmpeg_encoder_set_frame_yuv_from_rgb(uint8_t *rgb) {const int in_linesize[1] = { 3 * c->width };sws_context = sws_getCachedContext(sws_context,c->width, c->height, AV_PIX_FMT_RGB24,c->width, c->height, AV_PIX_FMT_YUV420P,0, 0, 0, 0);sws_scale(sws_context, (const uint8_t * const *)&rgb, in_linesize, 0,c->height, frame->data, frame->linesize);}uint8_t* generate_rgb(int width, int height, int pts, uint8_t *rgb) {int x, y, cur;rgb = (uint8_t *)realloc(rgb, 3 * sizeof(uint8_t) * height * width);for (y = 0; y < height; y++) {for (x = 0; x < width; x++) {cur = 3 * (y * width + x);rgb[cur + 0] = 0;rgb[cur + 1] = 0;rgb[cur + 2] = 0;if ((frame->pts / 25) % 2 == 0) {if (y < height / 2) {if (x < width / 2) {/* Black. */}else {rgb[cur + 0] = 255;}}else {if (x < width / 2) {rgb[cur + 1] = 255;}else {rgb[cur + 2] = 255;}}}else {if (y < height / 2) {rgb[cur + 0] = 255;if (x < width / 2) {rgb[cur + 1] = 255;}else {rgb[cur + 2] = 255;}}else {if (x < width / 2) {rgb[cur + 1] = 255;rgb[cur + 2] = 255;}else {rgb[cur + 0] = 255;rgb[cur + 1] = 255;rgb[cur + 2] = 255;}}}}}return rgb;}/* Allocate resources and write header data to the output file. */void ffmpeg_encoder_start(const char *filename, int codec_id, int fps, int width, int height) {AVCodec *codec;int ret;codec = avcodec_find_encoder((AVCodecID)codec_id);if (!codec) {fprintf(stderr, "Codec not found\n");exit(1);}c = avcodec_alloc_context3(codec);if (!c) {fprintf(stderr, "Could not allocate video codec context\n");exit(1);}c->bit_rate = 400000;c->width = width;c->height = height;c->time_base.num = 1;c->time_base.den = fps;c->keyint_min = 600;c->pix_fmt = AV_PIX_FMT_YUV420P;if (codec_id == AV_CODEC_ID_H264)av_opt_set(c->priv_data, "preset", "slow", 0);if (avcodec_open2(c, codec, NULL) < 0) {fprintf(stderr, "Could not open codec\n");exit(1);}file = fopen(filename, "wb");if (!file) {fprintf(stderr, "Could not open %s\n", filename);exit(1);}frame = av_frame_alloc();if (!frame) {fprintf(stderr, "Could not allocate video frame\n");exit(1);}frame->format = c->pix_fmt;frame->width = c->width;frame->height = c->height;ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, c->pix_fmt, 32);if (ret < 0) {fprintf(stderr, "Could not allocate raw picture buffer\n");exit(1);}}/*Write trailing data to the output fileand free resources allocated by ffmpeg_encoder_start.*/void ffmpeg_encoder_finish(void) {uint8_t endcode[] = { 0, 0, 1, 0xb7 };int got_output, ret;do {fflush(stdout);ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);if (ret < 0) {fprintf(stderr, "Error encoding frame\n");exit(1);}if (got_output) {fwrite(pkt.data, 1, pkt.size, file);av_packet_unref(&pkt);}} while (got_output);fwrite(endcode, 1, sizeof(endcode), file);fclose(file);avcodec_close(c);av_free(c);av_freep(&frame->data[0]);av_frame_free(&frame);}/*Encode one frame from an RGB24 input and save it to the output file.Must be called after ffmpeg_encoder_start, and ffmpeg_encoder_finishmust be called after the last call to this function.*/void ffmpeg_encoder_encode_frame(uint8_t *rgb) {int ret, got_output;ffmpeg_encoder_set_frame_yuv_from_rgb(rgb);av_init_packet(&pkt);pkt.data = NULL;pkt.size = 0;if (frame->pts == 1) {frame->key_frame = 1;frame->pict_type = AV_PICTURE_TYPE_I;}else {frame->key_frame = 0;frame->pict_type = AV_PICTURE_TYPE_P;}ret = avcodec_encode_video2(c, &pkt, frame, &got_output);if (ret < 0) {fprintf(stderr, "Error encoding frame\n");exit(1);}if (got_output) {fwrite(pkt.data, 1, pkt.size, file);av_packet_unref(&pkt);}}/* Represents the main loop of an application which generates one frame per loop. */static void encode_example(const char *filename, int codec_id) {int pts;int width = 320;int height = 240;uint8_t *rgb = NULL;ffmpeg_encoder_start(filename, codec_id, 25, width, height);for (pts = 0; pts < 100; pts++) {frame->pts = pts;rgb = generate_rgb(width, height, pts, rgb);ffmpeg_encoder_encode_frame(rgb);}ffmpeg_encoder_finish();}int main(void) {avcodec_register_all();encode_example("tmp.h264", AV_CODEC_ID_H264);encode_example("tmp.mpg", AV_CODEC_ID_MPEG1VIDEO);return 0;}

用的VS编译可以直接运行。

到FFmpeg官网上下载windows 预编译好的库文件即可；FFmpeg头文件及.lib文件存在于 Windows 64/32-bit  Dev包中，.dll文件存在于  Windows 64/32-bit  Shared包中。