[FFmpeg-devel] [PATCH V2] doc/examples: Add a qsv encoder example

Li, Zhong zhong.li at intel.com
Mon Aug 7 05:45:37 EEST 2017


> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Steven Liu
> Sent: Wednesday, August 2, 2017 2:01 PM
> To: FFmpeg development discussions and patches
> <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH V2] doc/examples: Add a qsv encoder
> example
> 
> 2017-08-03 1:27 GMT+08:00 Zhong Li <zhong.li at intel.com>:
> > It is an evolution from the exmaple "encode_video.c" to support qsv
> encoder.
> >
> > V1->V2: Split to a separated qsv encoding example, instead of a patch
> > based on encode_video.c
> >
> > Signed-off-by: Zhong Li <zhong.li at intel.com>
> > ---
> >  configure             |   2 +
> >  doc/Makefile          |   1 +
> >  doc/examples/qsvenc.c | 211
> > ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 214 insertions(+)
> >  create mode 100644 doc/examples/qsvenc.c
> >
> > diff --git a/configure b/configure
> > index 66c7b94..676cd85 100755
> > --- a/configure
> > +++ b/configure
> > @@ -1472,6 +1472,7 @@ EXAMPLE_LIST="
> >      metadata_example
> >      muxing_example
> >      qsvdec_example
> > +    qsvenc_example
> >      remuxing_example
> >      resampling_audio_example
> >      scaling_video_example
> > @@ -3213,6 +3214,7 @@ hw_decode_example_deps="avcodec avformat
> avutil"
> >  metadata_example_deps="avformat avutil"
> >  muxing_example_deps="avcodec avformat avutil swscale"
> >  qsvdec_example_deps="avcodec avutil libmfx h264_qsv_decoder"
> > +qsvenc_example_deps="avcodec avutil libmfx"
> >  remuxing_example_deps="avcodec avformat avutil"
> >  resampling_audio_example_deps="avutil swresample"
> >  scaling_video_example_deps="avutil swscale"
> > diff --git a/doc/Makefile b/doc/Makefile index b670f0b..ed41763 100644
> > --- a/doc/Makefile
> > +++ b/doc/Makefile
> > @@ -52,6 +52,7 @@ DOC_EXAMPLES-$(CONFIG_HW_DECODE_EXAMPLE)
> += hw_decode
> >  DOC_EXAMPLES-$(CONFIG_METADATA_EXAMPLE)          +=
> metadata
> >  DOC_EXAMPLES-$(CONFIG_MUXING_EXAMPLE)            +=
> muxing
> >  DOC_EXAMPLES-$(CONFIG_QSVDEC_EXAMPLE)            += qsvdec
> > +DOC_EXAMPLES-$(CONFIG_QSVENC_EXAMPLE)            += qsvenc
> >  DOC_EXAMPLES-$(CONFIG_REMUXING_EXAMPLE)          +=
> remuxing
> >  DOC_EXAMPLES-$(CONFIG_RESAMPLING_AUDIO_EXAMPLE)  +=
> resampling_audio
> >  DOC_EXAMPLES-$(CONFIG_SCALING_VIDEO_EXAMPLE)     +=
> scaling_video
> > diff --git a/doc/examples/qsvenc.c b/doc/examples/qsvenc.c new file
> > mode 100644 index 0000000..3b94cc8
> > --- /dev/null
> > +++ b/doc/examples/qsvenc.c
> > @@ -0,0 +1,211 @@
> > +/*
> > + * Copyright (c) 2017 Fabrice Bellard, Zhong Li
> > + *
> > + * 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.
> > + */
> > +
> > +/**
> > + * @file
> > + * Intel QSV-accelerated encoding example
> > + *
> > + * @example qsvenc.c
> > + */
> > +
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +
> > +#include <libavcodec/avcodec.h>
> > +
> > +#include <libavutil/opt.h>
> > +#include <libavutil/imgutils.h>
> > +#include "libavutil/buffer.h"
> > +#include "libavutil/hwcontext.h"
> > +
> > +static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket
> *pkt,
> > +                   FILE *outfile)
> > +{
> > +    int ret;
> > +
> > +    /* send the frame to the encoder */
> > +    if (frame)
> > +        printf("Send frame %3"PRId64"\n", frame->pts);
> > +
> > +    ret = avcodec_send_frame(enc_ctx, frame);
> > +    if (ret < 0) {
> > +        fprintf(stderr, "Error sending a frame for encoding\n");
> > +        exit(1);
> > +    }
> > +
> > +    while (ret >= 0) {
> > +        ret = avcodec_receive_packet(enc_ctx, pkt);
> > +        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
> > +            return;
> > +        else if (ret < 0) {
> > +            fprintf(stderr, "Error during encoding\n");
> > +            exit(1);
> > +        }
> > +
> > +        printf("Write packet %3"PRId64" (size=%5d)\n", pkt->pts,
> pkt->size);
> > +        fwrite(pkt->data, 1, pkt->size, outfile);
> > +        av_packet_unref(pkt);
> > +    }
> > +}
> > +
> > +int main(int argc, char **argv)
> > +{
> > +    const char *filename, *codec_name;
> > +    const AVCodec *codec;
> > +    AVCodecContext *c= NULL;
> Why don't use AVCodecParameters?

Could you give more detail about the reason? 
AVCodecParameters is used for encoded bitstream. Here just encoding a raw yuv, seems AVCodecContext is enough.

> > +    int i, ret, x, y;
> > +    FILE *f;
> > +    AVFrame *frame;
> > +    AVPacket *pkt;
> > +    AVBufferRef *encode_device = NULL;
> > +
> > +    if (argc <= 2) {
> > +        fprintf(stderr, "Usage: %s <output file> <codec name>\n",
> argv[0]);
> > +        exit(0);
> > +    }
> > +    filename = argv[1];
> > +    codec_name = argv[2];
> > +
> > +    if (!strstr(codec_name, "qsv")) {
> > +        fprintf(stderr, "no qsv codec found\n");
> > +        exit(0);
> > +    }
> > +
> > +    avcodec_register_all();
> > +
> > +    /* open the qsv hardware device */
> > +    ret = av_hwdevice_ctx_create(&encode_device,
> AV_HWDEVICE_TYPE_QSV,
> > +                                 NULL, NULL, 0);
> > +    if (ret < 0) {
> > +        fprintf(stderr, "Cannot open the hardware device\n");
> > +        exit(1);
> > +    }
> > +
> > +    /* find the encoder */
> > +    codec = avcodec_find_encoder_by_name(codec_name);
> > +    if (!codec) {
> > +        fprintf(stderr, "Codec '%s' not found\n", codec_name);
> > +        exit(1);
> > +    }
> > +
> > +    c = avcodec_alloc_context3(codec);
> > +    if (!c) {
> > +        fprintf(stderr, "Could not allocate video codec context\n");
> > +        exit(1);
> > +    }
> > +
> > +    pkt = av_packet_alloc();
> > +    if (!pkt)
> > +        exit(1);
> > +
> > +    /* put sample parameters */
> > +    c->bit_rate = 400000;
> > +    /* resolution must be a multiple of two */
> > +    c->width = 352;
> > +    c->height = 288;
> > +    /* frames per second */
> > +    c->time_base = (AVRational){1, 25};
> > +    c->framerate = (AVRational){25, 1};
> > +
> > +    /* emit one intra frame every ten frames
> > +     * check frame pict_type before passing frame
> > +     * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
> > +     * then gop_size is ignored and the output of encoder
> > +     * will always be I frame irrespective to gop_size
> > +     */
> > +    c->gop_size = 10;
> > +    c->max_b_frames = 1;
> > +    c->pix_fmt = AV_PIX_FMT_NV12;
> > +    c->hw_device_ctx = av_buffer_ref(encode_device);
> > +
> > +    /* open it */
> > +    ret = avcodec_open2(c, codec, NULL);
> > +    if (ret < 0) {
> > +        fprintf(stderr, "Could not open codec: %s\n", av_err2str(ret));
> > +        exit(1);
> > +    }
> > +
> > +    f = fopen(filename, "wb");
> > +    if (!f) {
> > +        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_frame_get_buffer(frame, 32);
> > +    if (ret < 0) {
> > +        fprintf(stderr, "Could not allocate the video frame data\n");
> > +        exit(1);
> > +    }
> > +
> > +    /* encode 1 second of video */
> > +    for (i = 0; i < 25; i++) {
> > +        fflush(stdout);
> > +
> > +        /* make sure the frame data is writable */
> > +        ret = av_frame_make_writable(frame);
> > +        if (ret < 0)
> > +            exit(1);
> > +
> > +        /* prepare a dummy image */
> > +        /* Y */
> > +        for (y = 0; y < c->height; y++) {
> > +            for (x = 0; x < c->width; x++) {
> > +                frame->data[0][y * frame->linesize[0] + x] = x + y + i *
> 3;
> > +            }
> > +        }
> > +
> > +        /* Cb and Cr */
> > +        for (y = 0; y < c->height/2; y++) {
> > +            for (x = 0; x < c->width/2; x++) {
> > +                frame->data[1][y * frame->linesize[1] + 2 * x] = 128 +
> y + i * 2;
> > +                frame->data[1][y * frame->linesize[1] + 2 * x + 1] = 64
> + x + i * 5;
> > +            }
> > +        }
> > +
> > +        frame->pts = i;
> > +
> > +        /* encode the image */
> > +        encode(c, frame, pkt, f);
> > +    }
> > +
> > +    /* flush the encoder */
> > +    encode(c, NULL, pkt, f);
> > +
> > +    fclose(f);
> > +
> > +    avcodec_free_context(&c);
> > +    av_frame_free(&frame);
> > +    av_packet_free(&pkt);
> > +    av_buffer_unref(&encode_device);
> > +
> > +    return 0;
> > +}
> > --
> > 1.8.3.1
> >
> > _______________________________________________
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> > ffmpeg-devel at ffmpeg.org
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