Encode yuv data into h264 data, use hardware encoding, and bind the hardware encoding to the codec context. * At the same time, a hardware encoding frame is created. After binding the hardware encoding context, the use is the same as the previous codec The context is the same.
ffmpeg_sample interpretation_vaapi_encode – Nuggets
/**
* @file
* Intel VAAPI-accelerated encoding example.
*
* @example vaapi_encode.c
* This example shows how to do VAAPI-accelerated encoding. now only supports NV12
* raw file, usage like: vaapi_encode 1920 1080 input.yuv output.h264
*
*/
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <libavcodec/avcodec.h>
#include <libavutil/pixdesc.h>
#include <libavutil/hwcontext.h>
static int width, height;
static AVBufferRef *hw_device_ctx = NULL;
static int set_hwframe_ctx(AVCodecContext *ctx, AVBufferRef *hw_device_ctx)
{
AVBufferRef *hw_frames_ref;
AVHWFramesContext *frames_ctx = NULL;
int err = 0;
//Create another reference
if (!(hw_frames_ref = av_hwframe_ctx_alloc(hw_device_ctx))) {
fprintf(stderr, "Failed to create VAAPI frame context.\
");
return -1;
}
//Set corresponding parameters
frames_ctx = (AVHWFramesContext *)(hw_frames_ref->data);
frames_ctx->format = AV_PIX_FMT_VAAPI;
frames_ctx->sw_format = AV_PIX_FMT_NV12;
frames_ctx->width = width;
frames_ctx->height = height;
frames_ctx->initial_pool_size = 20;
//Initialize
if ((err = av_hwframe_ctx_init(hw_frames_ref)) < 0) {
fprintf(stderr, "Failed to initialize VAAPI frame context."
"Error code: %s\
",av_err2str(err));
av_buffer_unref( & amp;hw_frames_ref);
return err;
}
//Associate this buffer with the encoding context and copy an additional reference. When using the codec later, use the hardware codec directly.
ctx->hw_frames_ctx = av_buffer_ref(hw_frames_ref);
if (!ctx->hw_frames_ctx)
err = AVERROR(ENOMEM);
av_buffer_unref( & amp;hw_frames_ref);
return err;
}
static int encode_write(AVCodecContext *avctx, AVFrame *frame, FILE *fout)
{
int ret = 0;
AVPacket enc_pkt;
av_init_packet( & amp;enc_pkt);
enc_pkt.data = NULL;
enc_pkt.size = 0;
//The data is sent to the encoder, the packet is taken out and written to the file.
if ((ret = avcodec_send_frame(avctx, frame)) < 0) {
fprintf(stderr, "Error code: %s\
", av_err2str(ret));
goto end;
}
while (1) {
ret = avcodec_receive_packet(avctx, & amp;enc_pkt);
if (ret)
break;
enc_pkt.stream_index = 0;
ret = fwrite(enc_pkt.data, enc_pkt.size, 1, fout);
av_packet_unref( & amp;enc_pkt);
}
end:
ret = ((ret == AVERROR(EAGAIN)) ? 0 : -1);
return ret;
}
/**
* Encode yuv data into h264 data, using hardware encoding,
* vaapi_encode 1920 1080 input.yuv output.h264
* @param argc
* @param argv
* @return
*/
int vaapi_encode_main(int argc, char *argv[])
{
int size, err;
FILE *fin = NULL, *fout = NULL;
AVFrame *sw_frame = NULL, *hw_frame = NULL;
AVCodecContext *avctx = NULL;
AVCodec *codec = NULL;
const char *enc_name = "h264_vaapi";
if (argc < 5) {
fprintf(stderr, "Usage: %s <width> <height> <input file> <output file>\
", argv[0]);
return -1;
}
//string to int
width = atoi(argv[1]);
height = atoi(argv[2]);
size = width * height;
//Read input file
if (!(fin = fopen(argv[3], "r"))) {
fprintf(stderr, "Fail to open input file : %s\
", strerror(errno));
return -1;
}
//Open the output file w + Write at the end of the file regardless of where the file pointer is b Open the file in binary form
if (!(fout = fopen(argv[4], "w + b"))) {
fprintf(stderr, "Fail to open output file : %s\
", strerror(errno));
err = -1;
goto close;
}
//Create hardware driver and initialize driver context
err = av_hwdevice_ctx_create( & amp;hw_device_ctx, AV_HWDEVICE_TYPE_VAAPI,
NULL, NULL, 0);
if (err < 0) {
fprintf(stderr, "Failed to create a VAAPI device. Error code: %s\
", av_err2str(err));
goto close;
}
//find the encoder
if (!(codec = avcodec_find_encoder_by_name(enc_name))) {
fprintf(stderr, "Could not find encoder.\
");
err = -1;
goto close;
}
//Allocate encoder context space
if (!(avctx = avcodec_alloc_context3(codec))) {
err = AVERROR(ENOMEM);
goto close;
}
//Set the parameters of the encoder context
avctx->width = width;
avctx->height = height;
//Time base and frame rate
avctx->time_base = (AVRational){1, 25};
avctx->framerate = (AVRational){25, 1};//
//template aspect ratio width/height
avctx->sample_aspect_ratio = (AVRational){1, 1};
avctx->pix_fmt = AV_PIX_FMT_VAAPI;
/* set hw_frames_ctx for encoder's AVCodecContext */
//Set hardware buffer context
if ((err = set_hwframe_ctx(avctx, hw_device_ctx)) < 0) {
fprintf(stderr, "Failed to set hwframe context.\
");
goto close;
}
//Open the encoding and decoding context
if ((err = avcodec_open2(avctx, codec, NULL)) < 0) {
fprintf(stderr, "Cannot open video encoder codec. Error code: %s\
", av_err2str(err));
goto close;
}
while (1) {
if (!(sw_frame = av_frame_alloc())) {
err = AVERROR(ENOMEM);
goto close;
}
/* read data into software frame, and transfer them into hw frame */
sw_frame->width = width;
sw_frame->height = height;
sw_frame->format = AV_PIX_FMT_NV12;
// Fill the AVFrame.data and AVFrame.buf arrays of the frame
if ((err = av_frame_get_buffer(sw_frame, 0)) < 0)
goto close;
//size is the image width*height at this time
//Read 1 size data from the file into data[0] of the frame
if ((err = fread((uint8_t*)(sw_frame->data[0]), size, 1, fin)) <= 0)
break;
//Read 1 size/2 size data from the file into data[0] of the frame
if ((err = fread((uint8_t*)(sw_frame->data[1]), size/2, 1, fin)) <= 0)
break;
if (!(hw_frame = av_frame_alloc())) {
err = AVERROR(ENOMEM);
goto close;
}
//Bind the newly allocated hw_frame to hw_frames_ctx, and bind the hardware frame to the hardware context. There is no data in the hardware frame at this time
if ((err = av_hwframe_get_buffer(avctx->hw_frames_ctx, hw_frame, 0)) < 0) {
fprintf(stderr, "Error code: %s.\
", av_err2str(err));
goto close;
}
if (!hw_frame->hw_frames_ctx) {
err = AVERROR(ENOMEM);
goto close;
}
//Copy the original data to the hardware buffer from sw_frame to hw_frame. At this time, there is data in the hardware frame.
if ((err = av_hwframe_transfer_data(hw_frame, sw_frame, 0)) < 0) {
fprintf(stderr, "Error while transferring frame data to surface."
"Error code: %s.\
", av_err2str(err));
goto close;
}
//Encode and write out to file. Note that hardware frames are used here.
if ((err = (encode_write(avctx, hw_frame, fout))) < 0) {
fprintf(stderr, "Failed to encode.\
");
goto close;
}
av_frame_free( & amp;hw_frame);
av_frame_free( & amp;sw_frame);
}
/* flush encoder */
//Refresh buffer data
err = encode_write(avctx, NULL, fout);
if (err == AVERROR_EOF)
err = 0;
close:
if (fin)
fclose(fin);
if(fout)
fclose(fout);
av_frame_free( & amp;sw_frame);
av_frame_free( & amp;hw_frame);
avcodec_free_context( & amp;avctx);
av_buffer_unref( & amp;hw_device_ctx);
return err;
}
Author: wonderful world
Link: https://juejin.cn/post/6895657345419608078
Source: Rare Earth Nuggets
Copyright belongs to the author. For commercial reprinting, please contact the author for authorization. For non-commercial reprinting, please indicate the source.