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-rw-r--r--src/Makefile5
-rw-r--r--src/advtime.c182
-rw-r--r--src/decoder.c207
3 files changed, 394 insertions, 0 deletions
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..f61114a
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1,5 @@
+CFLAGS=-std=c99 -Wall
+LibAV=`pkg-config --cflags --libs libavcodec`
+
+advtime: advtime.c
+ gcc ${LibAV} advtime.c -o $@
diff --git a/src/advtime.c b/src/advtime.c
new file mode 100644
index 0000000..a13aaa6
--- /dev/null
+++ b/src/advtime.c
@@ -0,0 +1,182 @@
+/**
+ * @file
+ * libavcodec API use example.
+ *
+ * @example libavcodec/api-example.c
+ * Note that this library only handles codecs (mpeg, mpeg4, etc...),
+ * not file formats (avi, vob, etc...). See library 'libavformat' for the
+ * format handling
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifdef HAVE_AV_CONFIG_H
+#undef HAVE_AV_CONFIG_H
+#endif
+
+#include <libavcodec/avcodec.h>
+#include <libavutil/audioconvert.h>
+#include <libavutil/common.h>
+#include <libavutil/imgutils.h>
+#include <libavutil/mathematics.h>
+#include <libavutil/samplefmt.h>
+
+#define INBUF_SIZE 4096
+#define AUDIO_INBUF_SIZE 20480
+#define AUDIO_REFILL_THRESH 4096
+
+/*
+ * Video decoding example
+ */
+
+static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
+ char *filename)
+{
+ FILE *f;
+ int i;
+
+ f=fopen(filename,"w");
+ fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255);
+ for(i=0;i<ysize;i++)
+ fwrite(buf + i * wrap,1,xsize,f);
+ fclose(f);
+}
+
+static void video_decode_example(const char *outfilename, const char *filename)
+{
+ AVCodec *codec;
+ AVCodecContext *c= NULL;
+ int frame, got_picture, len;
+ FILE *f;
+ AVFrame *picture;
+ uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
+ char buf[1024];
+ AVPacket avpkt;
+
+ av_init_packet(&avpkt);
+
+ /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
+ memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
+
+ printf("Video decoding\n");
+
+ /* find the mpeg1 video decoder */
+ codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO);
+ if (!codec) {
+ fprintf(stderr, "codec not found\n");
+ exit(1);
+ }
+
+ c = avcodec_alloc_context3(codec);
+ picture= avcodec_alloc_frame();
+
+ if(codec->capabilities&CODEC_CAP_TRUNCATED)
+ c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
+
+ /* For some codecs, such as msmpeg4 and mpeg4, width and height
+ MUST be initialized there because this information is not
+ available in the bitstream. */
+
+ /* open it */
+ if (avcodec_open2(c, codec, NULL) < 0) {
+ fprintf(stderr, "could not open codec\n");
+ exit(1);
+ }
+
+ /* the codec gives us the frame size, in samples */
+
+ f = fopen(filename, "rb");
+ if (!f) {
+ fprintf(stderr, "could not open %s\n", filename);
+ exit(1);
+ }
+
+ frame = 0;
+ for(;;) {
+ avpkt.size = fread(inbuf, 1, INBUF_SIZE, f);
+ if (avpkt.size == 0)
+ break;
+
+ /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
+ and this is the only method to use them because you cannot
+ know the compressed data size before analysing it.
+
+ BUT some other codecs (msmpeg4, mpeg4) are inherently frame
+ based, so you must call them with all the data for one
+ frame exactly. You must also initialize 'width' and
+ 'height' before initializing them. */
+
+ /* NOTE2: some codecs allow the raw parameters (frame size,
+ sample rate) to be changed at any frame. We handle this, so
+ you should also take care of it */
+
+ /* here, we use a stream based decoder (mpeg1video), so we
+ feed decoder and see if it could decode a frame */
+ avpkt.data = inbuf;
+ while (avpkt.size > 0) {
+ len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
+ if (len < 0) {
+ fprintf(stderr, "Error while decoding frame %d\n", frame);
+ exit(1);
+ }
+ if (got_picture) {
+ printf("saving frame %3d\n", frame);
+ fflush(stdout);
+
+ /* the picture is allocated by the decoder. no need to
+ free it */
+ snprintf(buf, sizeof(buf), outfilename, frame);
+ pgm_save(picture->data[0], picture->linesize[0],
+ c->width, c->height, buf);
+ frame++;
+ }
+ avpkt.size -= len;
+ avpkt.data += len;
+ }
+ }
+
+ /* some codecs, such as MPEG, transmit the I and P frame with a
+ latency of one frame. You must do the following to have a
+ chance to get the last frame of the video */
+ avpkt.data = NULL;
+ avpkt.size = 0;
+ len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
+ if (got_picture) {
+ printf("saving last frame %3d\n", frame);
+ fflush(stdout);
+
+ /* the picture is allocated by the decoder. no need to
+ free it */
+ snprintf(buf, sizeof(buf), outfilename, frame);
+ pgm_save(picture->data[0], picture->linesize[0],
+ c->width, c->height, buf);
+ frame++;
+ }
+
+ fclose(f);
+
+ avcodec_close(c);
+ av_free(c);
+ avcodec_free_frame(&picture);
+ printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+ if (argc < 2)
+ return 1;
+
+ /* register all the codecs */
+ avcodec_register_all();
+
+// FILE *fh = fopen(argv[1], "rb");
+// if (fh == NULL)
+// return 1;
+
+ video_decode_example(argv[1], filename);
+
+// fclose(sh);
+ return 0;
+}
diff --git a/src/decoder.c b/src/decoder.c
new file mode 100644
index 0000000..be4f7b4
--- /dev/null
+++ b/src/decoder.c
@@ -0,0 +1,207 @@
+/*
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * libavcodec API use example.
+ *
+ * @example libavcodec/api-example.c
+ * Note that this library only handles codecs (mpeg, mpeg4, etc...),
+ * not file formats (avi, vob, etc...). See library 'libavformat' for the
+ * format handling
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifdef HAVE_AV_CONFIG_H
+#undef HAVE_AV_CONFIG_H
+#endif
+
+#include "libavcodec/avcodec.h"
+#include "libavutil/audioconvert.h"
+#include "libavutil/common.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/samplefmt.h"
+
+#define INBUF_SIZE 4096
+#define AUDIO_INBUF_SIZE 20480
+#define AUDIO_REFILL_THRESH 4096
+
+/*
+ * Video decoding example
+ */
+
+static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
+ char *filename)
+{
+ FILE *f;
+ int i;
+
+ f=fopen(filename,"w");
+ fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255);
+ for(i=0;i<ysize;i++)
+ fwrite(buf + i * wrap,1,xsize,f);
+ fclose(f);
+}
+
+static void video_decode_example(const char *outfilename, const char *filename)
+{
+ AVCodec *codec;
+ AVCodecContext *c= NULL;
+ int frame, got_picture, len;
+ FILE *f;
+ AVFrame *picture;
+ uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
+ char buf[1024];
+ AVPacket avpkt;
+
+ av_init_packet(&avpkt);
+
+ /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
+ memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
+
+ printf("Video decoding\n");
+
+ /* find the mpeg1 video decoder */
+ codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO);
+ if (!codec) {
+ fprintf(stderr, "codec not found\n");
+ exit(1);
+ }
+
+ c = avcodec_alloc_context3(codec);
+ picture= avcodec_alloc_frame();
+
+ if(codec->capabilities&CODEC_CAP_TRUNCATED)
+ c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
+
+ /* For some codecs, such as msmpeg4 and mpeg4, width and height
+ MUST be initialized there because this information is not
+ available in the bitstream. */
+
+ /* open it */
+ if (avcodec_open2(c, codec, NULL) < 0) {
+ fprintf(stderr, "could not open codec\n");
+ exit(1);
+ }
+
+ /* the codec gives us the frame size, in samples */
+
+ f = fopen(filename, "rb");
+ if (!f) {
+ fprintf(stderr, "could not open %s\n", filename);
+ exit(1);
+ }
+
+ frame = 0;
+ for(;;) {
+ avpkt.size = fread(inbuf, 1, INBUF_SIZE, f);
+ if (avpkt.size == 0)
+ break;
+
+ /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
+ and this is the only method to use them because you cannot
+ know the compressed data size before analysing it.
+
+ BUT some other codecs (msmpeg4, mpeg4) are inherently frame
+ based, so you must call them with all the data for one
+ frame exactly. You must also initialize 'width' and
+ 'height' before initializing them. */
+
+ /* NOTE2: some codecs allow the raw parameters (frame size,
+ sample rate) to be changed at any frame. We handle this, so
+ you should also take care of it */
+
+ /* here, we use a stream based decoder (mpeg1video), so we
+ feed decoder and see if it could decode a frame */
+ avpkt.data = inbuf;
+ while (avpkt.size > 0) {
+ len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
+ if (len < 0) {
+ fprintf(stderr, "Error while decoding frame %d\n", frame);
+ exit(1);
+ }
+ if (got_picture) {
+ printf("saving frame %3d\n", frame);
+ fflush(stdout);
+
+ /* the picture is allocated by the decoder. no need to
+ free it */
+ snprintf(buf, sizeof(buf), outfilename, frame);
+ pgm_save(picture->data[0], picture->linesize[0],
+ c->width, c->height, buf);
+ frame++;
+ }
+ avpkt.size -= len;
+ avpkt.data += len;
+ }
+ }
+
+ /* some codecs, such as MPEG, transmit the I and P frame with a
+ latency of one frame. You must do the following to have a
+ chance to get the last frame of the video */
+ avpkt.data = NULL;
+ avpkt.size = 0;
+ len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
+ if (got_picture) {
+ printf("saving last frame %3d\n", frame);
+ fflush(stdout);
+
+ /* the picture is allocated by the decoder. no need to
+ free it */
+ snprintf(buf, sizeof(buf), outfilename, frame);
+ pgm_save(picture->data[0], picture->linesize[0],
+ c->width, c->height, buf);
+ frame++;
+ }
+
+ fclose(f);
+
+ avcodec_close(c);
+ av_free(c);
+ avcodec_free_frame(&picture);
+ printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+ const char *filename;
+
+ /* register all the codecs */
+ avcodec_register_all();
+
+ if (argc <= 1) {
+ audio_encode_example("/tmp/test.mp2");
+ audio_decode_example("/tmp/test.sw", "/tmp/test.mp2");
+
+ video_encode_example("/tmp/test.mpg");
+ filename = "/tmp/test.mpg";
+ } else {
+ filename = argv[1];
+ }
+
+ // audio_decode_example("/tmp/test.sw", filename);
+ video_decode_example("/tmp/test%d.pgm", filename);
+
+ return 0;
+}
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