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// An example of how to use the FFmpeg HLS muxer without ever touching the disk. | |
// | |
// To compile: | |
// cc main.c -lavcodec -lavformat -lavutil | |
// | |
// To run: | |
// ffmpeg -hide_banner -loglevel error -f lavfi -i testsrc -pix_fmt yuv420p -f mpegts - | ./a.out | |
#include <unistd.h> | |
#include <libavcodec/avcodec.h> | |
#include <libavformat/avformat.h> | |
int write_packet(void *opaque, uint8_t *data, int size) | |
{ | |
printf("write packet %d to file %s\n", size, (char *)opaque); | |
return size; | |
} | |
int handle_io_open(struct AVFormatContext *s, AVIOContext **pb, const char *url, | |
int flags, AVDictionary **options) | |
{ | |
printf("handle io open %s\n", url); | |
uint8_t *buf = NULL; | |
size_t size = 4096; | |
buf = av_malloc(size); | |
*pb = avio_alloc_context(buf, size, 1, (void *)url, NULL, write_packet, NULL); | |
s->opaque = (void *)url; | |
return 0; | |
} | |
int handle_io_close(struct AVFormatContext *s, AVIOContext *pb) | |
{ | |
printf("handle io close %s\n", (char *)s->opaque); | |
avio_context_free(&pb); | |
return 0; | |
} | |
int main(int argc, char **argv) | |
{ | |
AVFormatContext *fmt_ctx; | |
uint8_t buf[188]; | |
AVPacket *pkt = av_packet_alloc(); | |
// the io: prefix can be anything but is necessary to trick the hls muxer into | |
// thinking this is not on disk | |
avformat_alloc_output_context2(&fmt_ctx, NULL, "hls", "io:example-prefix"); | |
fmt_ctx->io_open = handle_io_open; | |
fmt_ctx->io_close2 = handle_io_close; | |
avformat_new_stream(fmt_ctx, NULL); | |
avformat_write_header(fmt_ctx, NULL); | |
for (int i = 0;; i++) | |
{ | |
// read 188 byte packet from stdin | |
int size = read(0, buf, 188); | |
if (size <= 0) | |
break; | |
pkt->data = buf; | |
pkt->size = size; | |
pkt->pts = pkt->dts = i * 1000; | |
pkt->duration = 1; | |
av_write_frame(fmt_ctx, pkt); | |
} | |
av_write_trailer(fmt_ctx); | |
avformat_free_context(fmt_ctx); | |
return 0; | |
} |
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