/* * 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 libavcodec API example * * @example encode_video.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; uint8_t endcode[] = { 0, 0, 1, 0xb7 }; if (argc <= 2) { fprintf(stderr, "Usage: %s <output file> <codec name>\n", argv[0]); exit(0); } filename = argv[1]; codec_name = argv[2]; /* find the mpeg1video 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_YUV420P; if (codec->id == AV_CODEC_ID_H264) av_opt_set(c->priv_data, "preset", "slow", 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; 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. On the first round, the frame is fresh from av_frame_get_buffer() and therefore we know it is writable. But on the next rounds, encode() will have called avcodec_send_frame(), and the codec may have kept a reference to the frame in its internal structures, that makes the frame unwritable. av_frame_make_writable() checks that and allocates a new buffer for the frame only if necessary. */ ret = av_frame_make_writable(frame); if (ret < 0) exit(1); /* Prepare a dummy image. In real code, this is where you would have your own logic for filling the frame. FFmpeg does not care what you put in the frame. */ /* 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 the image */ encode(c, frame, pkt, f); } /* flush the encoder */ encode(c, NULL, pkt, f); /* Add sequence end code to have a real MPEG file. It makes only sense because this tiny examples writes packets directly. This is called "elementary stream" and only works for some codecs. To create a valid file, you usually need to write packets into a proper file format or protocol; see muxing.c. */ if (codec->id == AV_CODEC_ID_MPEG1VIDEO || codec->id == AV_CODEC_ID_MPEG2VIDEO) fwrite(endcode, 1, sizeof(endcode), f); fclose(f); avcodec_free_context(&c); av_frame_free(&frame); av_packet_free(&pkt); return 0;}
/*
* 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 libavcodec API example
*
* @example encode_video.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;
uint8_t endcode[] = { 0, 0, 1, 0xb7 };
if (argc <= 2) {
fprintf(stderr, "Usage: %s <output file> <codec name>\n", argv[0]);
exit(0);
}
filename = argv[1];
codec_name = argv[2];
/* find the mpeg1video 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_YUV420P;
if (codec->id == AV_CODEC_ID_H264)
av_opt_set(c->priv_data, "preset", "slow", 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;
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.
On the first round, the frame is fresh from av_frame_get_buffer()
and therefore we know it is writable.
But on the next rounds, encode() will have called
avcodec_send_frame(), and the codec may have kept a reference to
the frame in its internal structures, that makes the frame
unwritable.
av_frame_make_writable() checks that and allocates a new buffer
for the frame only if necessary.
*/
ret = av_frame_make_writable(frame);
if (ret < 0)
exit(1);
/* Prepare a dummy image.
In real code, this is where you would have your own logic for
filling the frame. FFmpeg does not care what you put in the
frame.
*/
/* 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 the image */
encode(c, frame, pkt, f);
}
/* flush the encoder */
encode(c, NULL, pkt, f);
/* Add sequence end code to have a real MPEG file.
It makes only sense because this tiny examples writes packets
directly. This is called "elementary stream" and only works for some
codecs. To create a valid file, you usually need to write packets
into a proper file format or protocol; see muxing.c.
*/
if (codec->id == AV_CODEC_ID_MPEG1VIDEO || codec->id == AV_CODEC_ID_MPEG2VIDEO)
fwrite(endcode, 1, sizeof(endcode), f);
fclose(f);
avcodec_free_context(&c);
av_frame_free(&frame);
av_packet_free(&pkt);
return 0;
}