ffmpeg使用bmp编码器把bgr24编码为bmp图像

version

#define LIBAVCODEC_VERSION_MAJOR 60

#define LIBAVCODEC_VERSION_MINOR 15

#define LIBAVCODEC_VERSION_MICRO 100

note

不使用AVOutputFormat

code

void CFfmpegOps::EncodeBGR24ToBMP(const char* infile, const char* width_str, const char* height_str, const char *outfile)
{if ((!infile) || (!width_str) || (!height_str) || (!outfile)){return;}int width = 0;int height = 0;AVFrame *avframe = nullptr;int frame_bytes = 0;AVPixelFormat src_fmt = AV_PIX_FMT_BGR24;int ret = -1;FILE *in_fp = nullptr;size_t n = 0;AVPacket *avpacket = nullptr;const AVCodec *encoder = nullptr;AVCodecContext *encoder_ctx = nullptr;FILE *out_fp = nullptr;try{width = std::stoi(width_str);height = std::stoi(height_str);}catch (const std::exception &e){return;}avframe = av_frame_alloc();if (!avframe){printf("av_frame_alloc error\n");goto end;}avframe->format = src_fmt;avframe->width = width;avframe->height = height;frame_bytes = av_image_get_buffer_size(src_fmt, width, height, 1);ret = av_frame_get_buffer(avframe, 0);if (ret < 0){printf("av_frame_get_buffer error(%s)\n", GetFfmpegERR(ret));goto end;}in_fp = fopen(infile, "rb");if (!in_fp){printf("fopen error\n");goto end;}n = fread(avframe->data[0], sizeof(uint8_t), frame_bytes, in_fp);if ((int)n != (frame_bytes)){printf("n != (frame_bytes)\n");goto end;}avpacket = av_packet_alloc();if (!avpacket){printf("av_packet_alloc error\n");goto end;}encoder = avcodec_find_encoder(AV_CODEC_ID_BMP);if (!encoder){printf("avcodec_find_encoder error\n");goto end;}encoder_ctx = avcodec_alloc_context3(encoder);if (!encoder_ctx){printf("avcodec_alloc_context3 error\n");goto end;}encoder_ctx->pix_fmt = src_fmt;encoder_ctx->width = width;encoder_ctx->height = height;encoder_ctx->time_base.num = 1;encoder_ctx->time_base.den = 25;encoder_ctx->framerate.num = 25;encoder_ctx->framerate.den = 1;encoder_ctx->bit_rate = frame_bytes * encoder_ctx->framerate.num * 8;ret = avcodec_open2(encoder_ctx, encoder, nullptr);if (ret < 0){printf("avcodec_open2 error(%s)\n", GetFfmpegERR(ret));goto end;}out_fp = fopen(outfile, "wb");if (!out_fp){printf("fopen error\n");goto end;}ret = avcodec_send_frame(encoder_ctx, avframe);if (ret != 0){printf("avcodec_send_frame error(%s)\n", GetFfmpegERR(ret));goto end;}while (1){ret = avcodec_receive_packet(encoder_ctx, avpacket);if (ret != 0){if (ret == AVERROR(EAGAIN)){continue;}printf("avcodec_receive_packet error(%s)\n", GetFfmpegERR(ret));break;}n = fwrite(avpacket->data, avpacket->size, sizeof(uint8_t), out_fp);av_packet_unref(avpacket);break;}end:if (out_fp){fclose(out_fp);out_fp = nullptr;}if (encoder_ctx){avcodec_free_context(&encoder_ctx);encoder_ctx = nullptr;}if (avpacket){av_packet_free(&avpacket);avpacket = nullptr;}if (in_fp){fclose(in_fp);in_fp = nullptr;}if (avframe){av_frame_free(&avframe);avframe = nullptr;}}