[FFmpeg-devel] [PATCH v2 4/4] doc: add example for user data unregistered SEI encoding
James Almer
jamrial at gmail.com
Fri May 14 00:22:02 EEST 2021
On 4/30/2021 11:23 PM, Brad Hards wrote:
> Signed-off-by: Brad Hards <bradh at frogmouth.net>
> ---
> configure | 2 +
> doc/examples/.gitignore | 1 +
> doc/examples/Makefile | 1 +
> doc/examples/Makefile.example | 1 +
> doc/examples/encode_unregistered.c | 205 +++++++++++++++++++++++++++++
> 5 files changed, 210 insertions(+)
> create mode 100644 doc/examples/encode_unregistered.c
>
> diff --git a/configure b/configure
> index 6580859ef2..1fad5b29ca 100755
> --- a/configure
> +++ b/configure
> @@ -1708,6 +1708,7 @@ EXAMPLE_LIST="
> demuxing_decoding_example
> encode_audio_example
> encode_video_example
> + encode_unregistered_example
> extract_mvs_example
> filter_audio_example
> filtering_audio_example
> @@ -3708,6 +3709,7 @@ decode_video_example_deps="avcodec avutil"
> demuxing_decoding_example_deps="avcodec avformat avutil"
> encode_audio_example_deps="avcodec avutil"
> encode_video_example_deps="avcodec avutil"
> +encode_unregistered_example_deps="avcodec avutil"
> extract_mvs_example_deps="avcodec avformat avutil"
> filter_audio_example_deps="avfilter avutil"
> filtering_audio_example_deps="avfilter avcodec avformat avutil"
> diff --git a/doc/examples/.gitignore b/doc/examples/.gitignore
> index 44960e1de7..d3f7739e68 100644
> --- a/doc/examples/.gitignore
> +++ b/doc/examples/.gitignore
> @@ -4,6 +4,7 @@
> /decode_video
> /demuxing_decoding
> /encode_audio
> +/encode_unregistered
> /encode_video
> /extract_mvs
> /filter_audio
> diff --git a/doc/examples/Makefile b/doc/examples/Makefile
> index 81bfd34d5d..00ef609c7b 100644
> --- a/doc/examples/Makefile
> +++ b/doc/examples/Makefile
> @@ -5,6 +5,7 @@ EXAMPLES-$(CONFIG_DECODE_VIDEO_EXAMPLE) += decode_video
> EXAMPLES-$(CONFIG_DEMUXING_DECODING_EXAMPLE) += demuxing_decoding
> EXAMPLES-$(CONFIG_ENCODE_AUDIO_EXAMPLE) += encode_audio
> EXAMPLES-$(CONFIG_ENCODE_VIDEO_EXAMPLE) += encode_video
> +EXAMPLES-$(CONFIG_ENCODE_UNREGISTERED_EXAMPLE) += encode_unregistered
> EXAMPLES-$(CONFIG_EXTRACT_MVS_EXAMPLE) += extract_mvs
> EXAMPLES-$(CONFIG_FILTER_AUDIO_EXAMPLE) += filter_audio
> EXAMPLES-$(CONFIG_FILTERING_AUDIO_EXAMPLE) += filtering_audio
> diff --git a/doc/examples/Makefile.example b/doc/examples/Makefile.example
> index a232d97f98..f26a6597f8 100644
> --- a/doc/examples/Makefile.example
> +++ b/doc/examples/Makefile.example
> @@ -18,6 +18,7 @@ EXAMPLES= avio_list_dir \
> demuxing_decoding \
> encode_audio \
> encode_video \
> + encode_unregistered \
> extract_mvs \
> filtering_video \
> filtering_audio \
> diff --git a/doc/examples/encode_unregistered.c b/doc/examples/encode_unregistered.c
> new file mode 100644
> index 0000000000..e9309460c0
> --- /dev/null
> +++ b/doc/examples/encode_unregistered.c
> @@ -0,0 +1,205 @@
> +/*
> + * Copyright (c) 2001 Fabrice Bellard
> + *
> + * 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
> + * video encoding with SEI (user unregistered) API example
> + *
> + * @example encode_unregistered.c
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include <libavcodec/avcodec.h>
> +
> +#include <libavutil/opt.h>
> +#include <libavutil/imgutils.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;
> + int i, ret, x, y;
> + FILE *f;
> + AVFrame *frame;
> + AVPacket *pkt;
> + AVFrameSideData *side_data;
> + // This is from MISB ST 2101
> + char sei_message[] = {0xa5, 0x50, 0x52, 0xaf, 0x52, 0x16, 0x5f, 0x45,
> + 0xa3, 0x18, 0x1c, 0xfc, 0x7a, 0xbb, 0xc2, 0x67,
> + 0x01, 0x70, 0xF5, 0x92, 0xF0, 0x23, 0x73, 0x36,
> + 0x4A, 0xF8, 0xAA, 0x91, 0x62, 0xC0, 0x0F, 0x2E,
> + 0xB2, 0xDA, 0x16, 0xB7, 0x43, 0x41, 0x00, 0x08,
> + 0x41, 0xA0, 0xBE, 0x36, 0x5B, 0x5A, 0xB9, 0x6A,
> + 0x36, 0x45};
> +
> + if (argc <= 2) {
> + fprintf(stderr, "Usage: %s <output file> <codec name>\n", argv[0]);
> + exit(0);
> + }
> + filename = argv[1];
> + codec_name = argv[2];
> +
> + 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);
> +
> + c->bit_rate = 400000;
> + c->width = 352;
> + c->height = 288;
> + /* frames per second */
> + c->time_base = (AVRational){1, 25};
> + c->framerate = (AVRational){25, 1};
> + c->gop_size = 10;
> + c->max_b_frames = 0;
> + c->pix_fmt = AV_PIX_FMT_YUV420P;
> + if (codec->id == AV_CODEC_ID_H264)
> + av_opt_set(c->priv_data, "preset", "medium", 0);
> +
> + /* 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;
> + side_data = av_frame_new_side_data(frame, AV_FRAME_DATA_SEI_UNREGISTERED, sizeof(sei_message));
> + if (!side_data)
> + {
> + fprintf(stderr, "Could not allocate the video frame side data\n");
> + exit(1);
> + }
> + memcpy(side_data->data, sei_message, side_data->size);
This example is a simple encode API usage with the sole addition of
inserting one side data element to every frame. It's not really useful.
> +
> + ret = av_frame_get_buffer(frame, 0);
> + 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] + x] = 128 + y + i * 2;
> + frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
> + }
> + }
> +
> + frame->pts = i;
> + 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);
> +
> + return 0;
> +}
>
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