Added a movie thumbnailer (storyboard generator) using libavcodec.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@3345 92316355-f0b4-4df1-b90c-862c8a59935f

examples/Makefile.am

@@ -3,7 +3,7 @@
 AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/pipi -I../pipi
 
 noinst_PROGRAMS = edd img2rubik sharpen floodfill line bezier histogram \
-	colorstring
+	colorstring storyboard
 
 edd_SOURCES = edd.c
 edd_LDADD = ../pipi/libpipi.la
@@ -28,3 +28,9 @@ histogram_LDADD = ../pipi/libpipi.la
 
 colorstring_SOURCES = colorstring.c
 colorstring_LDADD = ../pipi/libpipi.la
+
+storyboard_SOURCES = storyboard.c
+storyboard_LDADD = ../pipi/libpipi.la
+storyboard_CFLAGS = `pkg-config --cflags libavformat libavcodec libswscale`
+storyboard_LDFLAGS = `pkg-config --libs libavformat libavcodec libswscale`
+

examples/storyboard.c

@@ -0,0 +1,184 @@
+/*
+ *  storyboard    generate a storyboard from a movie
+ *  Copyright (c) 2009 Sam Hocevar <sam@zoy.org>
+ *                All Rights Reserved
+ *
+ *  $Id$
+ *
+ *  This program is free software. It comes without any warranty, to
+ *  the extent permitted by applicable law. You can redistribute it
+ *  and/or modify it under the terms of the Do What The Fuck You Want
+ *  To Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <avcodec.h>
+#include <avformat.h>
+#include <swscale.h>
+
+#include <pipi.h>
+
+#define STEP 20
+
+#define TWIDTH 90
+#define THEIGHT 60
+#define TCOLS 10
+#define TROWS 200
+#define NTHUMBS (TCOLS*TROWS)
+
+int main(int argc, char *argv[])
+{
+    char fmtstr[1024];
+    AVPacket packet;
+    AVFormatContext *fmt;
+    AVCodecContext *ctx;
+    AVCodec *codec;
+    AVFrame *frame;
+    struct SwsContext *sws;
+    pipi_image_t *image;
+    pipi_pixels_t *p;
+    uint8_t *buffer;
+    char *parser;
+    int stream, i, n = 0, k = 0, idx = 0;
+
+    if(argc < 2)
+        return EXIT_FAILURE;
+
+    strcpy(fmtstr, argv[1]);
+    parser = strrchr(fmtstr, '.');
+    if(parser)
+        strcpy(parser, "%03i.jpeg");
+    else
+        strcat(fmtstr, "%03i.jpeg");
+
+    image = pipi_new(TWIDTH * TCOLS, THEIGHT * TROWS);
+    p = pipi_get_pixels(image, PIPI_PIXELS_RGBA_U8);
+    buffer = (uint8_t *)p->pixels;
+
+    av_register_all();
+    if(av_open_input_file(&fmt, argv[1], NULL, 0, NULL) != 0)
+        return EXIT_FAILURE;
+    if(av_find_stream_info(fmt) < 0 )
+        return EXIT_FAILURE;
+
+    stream = -1;
+    for(i = 0; stream == -1 && i < (int)fmt->nb_streams; i++)
+        if(fmt->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO)
+            stream = i;
+    if(stream == -1)
+        return EXIT_FAILURE;
+    ctx = fmt->streams[stream]->codec;
+
+    codec = avcodec_find_decoder(ctx->codec_id);
+    if(codec == NULL)
+        return EXIT_FAILURE;
+    if(avcodec_open(ctx, codec) < 0)
+        return EXIT_FAILURE;
+
+    frame = avcodec_alloc_frame();
+
+    sws = sws_getContext(ctx->width, ctx->height, ctx->pix_fmt,
+                         TWIDTH, THEIGHT, PIX_FMT_RGB32,
+                         SWS_BICUBIC, NULL, NULL, NULL);
+
+    for(;;)
+    {
+        int finished, ret;
+
+        ret = av_read_frame(fmt, &packet);
+
+        if(idx == NTHUMBS || (idx > 0 && ret < 0))
+        {
+            /* Only process every 20th image */
+            char buf[1024];
+            sprintf(buf, fmtstr, k++);
+            printf("saving %i thumbs in %s\n", idx, buf);
+            pipi_save(image, buf);
+            memset(buffer, 0, TWIDTH * TCOLS * THEIGHT * TROWS * 4);
+            idx = 0;
+        }
+
+        if(ret < 0)
+            break;
+
+        if(packet.stream_index != stream)
+        {
+            av_free_packet(&packet);
+            continue;
+        }
+
+        avcodec_decode_video(ctx, frame, &finished, packet.data, packet.size);
+        if(!finished)
+        {
+            av_free_packet(&packet);
+            continue;
+        }
+
+        n++;
+
+        if((n % STEP) == STEP / 2)
+        {
+            int pitch = TWIDTH * TCOLS * 4;
+            uint8_t *start;
+
+            start = buffer + (idx % TCOLS) * TWIDTH * 4
+                           + (idx / TCOLS) * TWIDTH * TCOLS * 4 * THEIGHT;
+
+            sws_scale(sws, frame->data, frame->linesize, 0, ctx->height,
+                      &start, &pitch);
+
+            /* Now check whether the new image is really different
+             * from the previous one (> 8% pixel changes) */
+            if(idx == 0)
+            {
+                idx++;
+            }
+            else
+            {
+                uint8_t *prev;
+                int x, y, t, a, b, changed = 0;
+
+                if(idx % TCOLS)
+                    prev = start - TWIDTH * 4;
+                else
+                    prev = start + (TCOLS - 1) * TWIDTH * 4
+                                 - TWIDTH * TCOLS * 4 * THEIGHT;
+
+                for(y = 0; y < THEIGHT; y++)
+                    for(x = 0; x < TWIDTH; x++)
+                    {
+                        int ok = 0;
+
+                        for(t = 0; t < 3; t++)
+                        {
+                            int offset = y * TWIDTH * TCOLS + x;
+                            a = start[offset * 4 + t];
+                            b = prev[offset * 4 + t];
+
+                            if(a < b - 5 || a > b + 5)
+                            {
+                                ok = 1;
+                                break;
+                            }
+                        }
+
+                        changed += ok;
+                    }
+
+                if(changed > TWIDTH * THEIGHT * 8 / 100)
+                    idx++;
+            }
+        }
+
+        av_free_packet(&packet);
+    }
+
+    return EXIT_SUCCESS;
+}
+