mpv/libmpcodecs/vf_screenshot.c

/*
 * This file is part of MPlayer.
 *
 * MPlayer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#include <libswscale/swscale.h>
#include <libavcodec/avcodec.h>

#include "mp_msg.h"
#include "img_format.h"
#include "mp_image.h"
#include "vf.h"
#include "vf_scale.h"
#include "fmt-conversion.h"


struct vf_priv_s {
    int frameno;
    char fname[102];
    /// shot stores current screenshot mode:
    /// 0: don't take screenshots
    /// 1: take single screenshot, reset to 0 afterwards
    /// 2: take screenshots of each frame
    int shot, store_slices;
    int dw, dh, stride;
    uint8_t *buffer;
    struct SwsContext *ctx;
    AVCodecContext *avctx;
    uint8_t *outbuffer;
    int outbuffer_size;
};

//===========================================================================//

static int config(struct vf_instance *vf,
                  int width, int height, int d_width, int d_height,
                  unsigned int flags, unsigned int outfmt)
{
    vf->priv->ctx=sws_getContextFromCmdLine(width, height, outfmt,
                                 d_width, d_height, IMGFMT_RGB24);

    vf->priv->outbuffer_size = d_width * d_height * 3 * 2;
    vf->priv->outbuffer = realloc(vf->priv->outbuffer, vf->priv->outbuffer_size);
    vf->priv->avctx->width = d_width;
    vf->priv->avctx->height = d_height;
    vf->priv->avctx->pix_fmt = PIX_FMT_RGB24;
    vf->priv->avctx->compression_level = 0;
    vf->priv->dw = d_width;
    vf->priv->dh = d_height;
    vf->priv->stride = (3*vf->priv->dw+15)&~15;

    free(vf->priv->buffer); // probably reconfigured
    vf->priv->buffer = NULL;

    return vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
}

static void write_png(struct vf_priv_s *priv)
{
    char *fname = priv->fname;
    FILE * fp;
    AVFrame pic;
    int size;

    fp = fopen (fname, "wb");
    if (fp == NULL) {
        mp_msg(MSGT_VFILTER,MSGL_ERR,"\nPNG Error opening %s for writing!\n", fname);
        return;
    }

    pic.data[0] = priv->buffer;
    pic.linesize[0] = priv->stride;
    size = avcodec_encode_video(priv->avctx, priv->outbuffer, priv->outbuffer_size, &pic);
    if (size > 0)
        fwrite(priv->outbuffer, size, 1, fp);

    fclose (fp);
}

static int fexists(char *fname)
{
    struct stat dummy;
    if (stat(fname, &dummy) == 0) return 1;
    else return 0;
}

static void gen_fname(struct vf_priv_s* priv)
{
    do {
        snprintf (priv->fname, 100, "shot%04d.png", ++priv->frameno);
    } while (fexists(priv->fname) && priv->frameno < 100000);
    if (fexists(priv->fname)) {
        priv->fname[0] = '\0';
        return;
    }

    mp_msg(MSGT_VFILTER,MSGL_INFO,"*** screenshot '%s' ***\n",priv->fname);

}

static void scale_image(struct vf_priv_s* priv, mp_image_t *mpi)
{
    uint8_t *dst[MP_MAX_PLANES] = {NULL};
    int dst_stride[MP_MAX_PLANES] = {0};

    dst_stride[0] = priv->stride;
    if (!priv->buffer)
        priv->buffer = av_malloc(dst_stride[0]*priv->dh);

    dst[0] = priv->buffer;
    sws_scale(priv->ctx, (const uint8_t **)mpi->planes, mpi->stride, 0, priv->dh, dst, dst_stride);
}

static void start_slice(struct vf_instance *vf, mp_image_t *mpi)
{
    vf->dmpi=vf_get_image(vf->next,mpi->imgfmt,
        mpi->type, mpi->flags, mpi->width, mpi->height);
    if (vf->priv->shot) {
        vf->priv->store_slices = 1;
        if (!vf->priv->buffer)
            vf->priv->buffer = av_malloc(vf->priv->stride*vf->priv->dh);
    }

}

static void draw_slice(struct vf_instance *vf, unsigned char** src,
                       int* stride, int w,int h, int x, int y)
{
    if (vf->priv->store_slices) {
        uint8_t *dst[MP_MAX_PLANES] = {NULL};
        int dst_stride[MP_MAX_PLANES] = {0};
        dst_stride[0] = vf->priv->stride;
        dst[0] = vf->priv->buffer;
        sws_scale(vf->priv->ctx, (const uint8_t **)src, stride, y, h, dst, dst_stride);
    }
    vf_next_draw_slice(vf,src,stride,w,h,x,y);
}

static void get_image(struct vf_instance *vf, mp_image_t *mpi)
{
    // FIXME: should vf.c really call get_image when using slices??
    if (mpi->flags & MP_IMGFLAG_DRAW_CALLBACK)
      return;
    vf->dmpi= vf_get_image(vf->next, mpi->imgfmt,
                           mpi->type, mpi->flags/* | MP_IMGFLAG_READABLE*/, mpi->width, mpi->height);

    for (int i = 0; i < MP_MAX_PLANES; i++) {
        mpi->planes[i]=vf->dmpi->planes[i];
        mpi->stride[i]=vf->dmpi->stride[i];
    }
    mpi->width=vf->dmpi->width;

    mpi->flags|=MP_IMGFLAG_DIRECT;

    mpi->priv=(void*)vf->dmpi;
}

static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts)
{
    mp_image_t *dmpi = (mp_image_t *)mpi->priv;

    if (mpi->flags & MP_IMGFLAG_DRAW_CALLBACK)
      dmpi = vf->dmpi;
    else
    if(!(mpi->flags&MP_IMGFLAG_DIRECT)){
        dmpi=vf_get_image(vf->next,mpi->imgfmt,
                                    MP_IMGTYPE_EXPORT, 0,
                                    mpi->width, mpi->height);
        vf_clone_mpi_attributes(dmpi, mpi);
        for (int i = 0; i < MP_MAX_PLANES; i++) {
            dmpi->planes[i]=mpi->planes[i];
            dmpi->stride[i]=mpi->stride[i];
        }
        dmpi->width=mpi->width;
        dmpi->height=mpi->height;
    }

    if(vf->priv->shot) {
        if (vf->priv->shot==1)
            vf->priv->shot=0;
        gen_fname(vf->priv);
        if (vf->priv->fname[0]) {
            if (!vf->priv->store_slices)
              scale_image(vf->priv, dmpi);
            write_png(vf->priv);
        }
        vf->priv->store_slices = 0;
    }

    return vf_next_put_image(vf, dmpi, pts);
}

static int control (vf_instance_t *vf, int request, void *data)
{
    /** data contains an integer argument
     * 0: take screenshot with the next frame
     * 1: take screenshots with each frame until the same command is given once again
     **/
    if(request==VFCTRL_SCREENSHOT) {
        if (data && *(int*)data) { // repeated screenshot mode
            if (vf->priv->shot==2)
                vf->priv->shot=0;
            else
                vf->priv->shot=2;
        } else { // single screenshot
            if (!vf->priv->shot)
                vf->priv->shot=1;
        }
        return CONTROL_TRUE;
    }
    return vf_next_control (vf, request, data);
}


//===========================================================================//

static int query_format(struct vf_instance *vf, unsigned int fmt)
{
    enum PixelFormat av_format = imgfmt2pixfmt(fmt);

    if (av_format != PIX_FMT_NONE && sws_isSupportedInput(av_format))
        return vf_next_query_format(vf, fmt);
    return 0;
}

static void uninit(vf_instance_t *vf)
{
    avcodec_close(vf->priv->avctx);
    av_freep(&vf->priv->avctx);
    if(vf->priv->ctx) sws_freeContext(vf->priv->ctx);
    av_free(vf->priv->buffer);
    free(vf->priv->outbuffer);
    free(vf->priv);
}

static int vf_open(vf_instance_t *vf, char *args)
{
    vf->config=config;
    vf->control=control;
    vf->put_image=put_image;
    vf->query_format=query_format;
    vf->start_slice=start_slice;
    vf->draw_slice=draw_slice;
    vf->get_image=get_image;
    vf->uninit=uninit;
    vf->priv=malloc(sizeof(struct vf_priv_s));
    vf->priv->frameno=0;
    vf->priv->shot=0;
    vf->priv->store_slices=0;
    vf->priv->buffer=0;
    vf->priv->outbuffer=0;
    vf->priv->ctx=0;
    vf->priv->avctx = avcodec_alloc_context();
    if (avcodec_open(vf->priv->avctx, avcodec_find_encoder(CODEC_ID_PNG))) {
        mp_msg(MSGT_VFILTER, MSGL_FATAL, "Could not open libavcodec PNG encoder\n");
        return 0;
    }
    return 1;
}


const vf_info_t vf_info_screenshot = {
    "screenshot to file",
    "screenshot",
    "A'rpi, Jindrich Makovicka",
    "",
    vf_open,
    NULL
};

//===========================================================================//