1

Тема: Відео-кодик на С++

Як розробити відео-кодик  на C++?
В кого є ідеї скидайте, наперед дякую.....

2

Re: Відео-кодик на С++

Підтримую тему, самому цікаво. Я якось пробував написати хоча б відео з функції виду:

int color(int x, int y, int frame);

Але попіксельно виводити щось в SDL дає недостатній FPS. Цікаво як такі проблеми вирішують в відеоплеєрах?

3

Re: Відео-кодик на С++

bunyk написав:

Цікаво як такі проблеми вирішують в відеоплеєрах?

Там не працюють з пікселями окремо, як правило картинка у відеопам_яті зберігається як довжилезний массив байт, наприклад - ргбргбргбргб... і працюють з ним як з массивом (наприклад щоб знебарвити картинку) я викорисовував свого часу такий код:

int middle;
char p[];
new p = %тут якийсь get пам_яті%

for (int i=0; i< widht-1; i++)
{
   for (j = 0; j < height-1; j++)
  {
    middle = (p[i*3+j+0] + p[i*3+j+1] + p[i*3+j+2] ) / 3;
    p[i*3+j+0] = middle;
    p[i*3+j+1] = middle;
    p[i*3+j+2] = middle;
  }
}

4

Re: Відео-кодик на С++

Oтак  напряму і писав до відеопам'яті ;) То розкажіть нам про відеорежими відеокарти й сторінки відеопам'яті.
Я розумію що кожна жаба своє болото хвалить, але те болото треба вказувати, бо це людей вводить у оману.

Подякували: bunyk1

5

Re: Відео-кодик на С++

Це все цікаво, але як створити відеокодек?

6

Re: Відео-кодик на С++

Вася, вам навряд-чи щось допоможе, бо ви не одрізняєте плюси од шарпа. Ідіть на фрілан.сру, збережіть свій час, бо підказки вам не потрібна - не зрозумієте (простіше кажучи - Мертві бджоли не гудуть!)

7 Востаннє редагувалося vasya6868 (24.04.2013 17:51:22)

Re: Відео-кодик на С++

Дякую за хороші підказки Очі.завидючі, але ти скинь щось а я сам вирішу чи я розберусь чи ні, а можливо ти нівчому не розбираєшся?))))без обід - кожен вміє говорити, в особливості такі як ти.....

8

Re: Відео-кодик на С++

vasya6868 написав:

Дякую за хороші підказки Очі.завидючі, але ти скинь щось а я сам вирішу чи я розберусь чи ні, а можливо ти нівчому не розбираєшся?))))без обід - кожен вміє говорити, в особливості такі як ти.....

Ну, якщо такий розумний і у всьому розбирається, то ось, розбирайся:

Прихований текст
/*
 * 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 <unistd.h>

#include "mp_msg.h"
#include "help_mp.h"
#include "mpcommon.h"

#include "osdep/timer.h"
#include "osdep/shmem.h"

#include "stream/stream.h"
#include "libmpdemux/demuxer.h"
#include "libmpdemux/parse_es.h"

#include "codec-cfg.h"

#include "libvo/video_out.h"

#include "libmpdemux/stheader.h"
#include "vd.h"
#include "vf.h"
#include "sub/eosd.h"

#include "dec_video.h"

#ifdef CONFIG_DYNAMIC_PLUGINS
#include <dlfcn.h>
#endif

#include "cpudetect.h"

int field_dominance = -1;

int divx_quality = 0;

const vd_functions_t *mpvdec = NULL;

int get_video_quality_max(sh_video_t *sh_video)
{
    vf_instance_t *vf = sh_video->vfilter;
    if (vf) {
        int ret = vf->control(vf, VFCTRL_QUERY_MAX_PP_LEVEL, NULL);
        if (ret > 0) {
            mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_UsingExternalPP, ret);
            return ret;
        }
    }
    if (mpvdec) {
        int ret = mpvdec->control(sh_video, VDCTRL_QUERY_MAX_PP_LEVEL, NULL);
        if (ret > 0) {
            mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_UsingCodecPP, ret);
            return ret;
        }
    }
//  mp_msg(MSGT_DECVIDEO,MSGL_INFO,"[PP] Sorry, postprocessing is not available\n");
    return 0;
}

void set_video_quality(sh_video_t *sh_video, int quality)
{
    vf_instance_t *vf = sh_video->vfilter;
    if (vf) {
        int ret = vf->control(vf, VFCTRL_SET_PP_LEVEL, &quality);
        if (ret == CONTROL_TRUE)
            return;             // success
    }
    if (mpvdec)
        mpvdec->control(sh_video, VDCTRL_SET_PP_LEVEL, &quality);
}

int set_video_colors(sh_video_t *sh_video, const char *item, int value)
{
    vf_instance_t *vf = sh_video->vfilter;
    vf_equalizer_t data;

    data.item  = item;
    data.value = value;

    mp_dbg(MSGT_DECVIDEO, MSGL_V, "set video colors %s=%d \n", item, value);
    if (vf) {
        int ret = vf->control(vf, VFCTRL_SET_EQUALIZER, &data);
        if (ret == CONTROL_TRUE)
            return 1;
    }
    /* try software control */
    if (mpvdec)
        if (mpvdec->control(sh_video, VDCTRL_SET_EQUALIZER, item,
                            (int *) value) == CONTROL_OK)
            return 1;
    mp_msg(MSGT_DECVIDEO, MSGL_V,
           "Video attribute '%s' is not supported by selected vo & vd.\n",
           item);
    return 0;
}

int get_video_colors(sh_video_t *sh_video, const char *item, int *value)
{
    vf_instance_t *vf = sh_video->vfilter;
    vf_equalizer_t data;

    data.item = item;

    mp_dbg(MSGT_DECVIDEO, MSGL_V, "get video colors %s \n", item);
    if (vf) {
        int ret = vf->control(vf, VFCTRL_GET_EQUALIZER, &data);
        if (ret == CONTROL_TRUE) {
            *value = data.value;
            return 1;
        }
    }
    /* try software control */
    if (mpvdec)
        return mpvdec->control(sh_video, VDCTRL_GET_EQUALIZER, item, value);
    return 0;
}

int set_rectangle(sh_video_t *sh_video, int param, int value)
{
    vf_instance_t *vf = sh_video->vfilter;
    int data[] = { param, value };

    mp_dbg(MSGT_DECVIDEO, MSGL_V, "set rectangle \n");
    if (vf) {
        int ret = vf->control(vf, VFCTRL_CHANGE_RECTANGLE, data);
        if (ret)
            return 1;
    }
    return 0;
}

void resync_video_stream(sh_video_t *sh_video)
{
    sh_video->timer            = 0;
    sh_video->next_frame_time  = 0;
    sh_video->num_buffered_pts = 0;
    sh_video->last_pts         = MP_NOPTS_VALUE;
    if (mpvdec)
        mpvdec->control(sh_video, VDCTRL_RESYNC_STREAM, NULL);
}

int get_current_video_decoder_lag(sh_video_t *sh_video)
{
    int ret;

    if (!mpvdec)
        return -1;
    ret = mpvdec->control(sh_video, VDCTRL_QUERY_UNSEEN_FRAMES, NULL);
    if (ret >= 10)
        return ret - 10;
    return -1;
}

void uninit_video(sh_video_t *sh_video)
{
    if (!sh_video->initialized)
        return;
    mp_msg(MSGT_DECVIDEO, MSGL_V, "Uninit video: %s\n", sh_video->codec->drv);
    mpvdec->uninit(sh_video);
    mpvdec = NULL;
#ifdef CONFIG_DYNAMIC_PLUGINS
    if (sh_video->dec_handle)
        dlclose(sh_video->dec_handle);
#endif
    vf_uninit_filter_chain(sh_video->vfilter);
    eosd_uninit();
    sh_video->initialized = 0;
}

void vfm_help(void)
{
    int i;
    mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_AvailableVideoFm);
    mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_VIDEO_DRIVERS\n");
    mp_msg(MSGT_DECVIDEO, MSGL_INFO, "   vfm:    info:  (comment)\n");
    for (i = 0; mpcodecs_vd_drivers[i] != NULL; i++)
        mp_msg(MSGT_DECVIDEO, MSGL_INFO, "%8s  %s (%s)\n",
               mpcodecs_vd_drivers[i]->info->short_name,
               mpcodecs_vd_drivers[i]->info->name,
               mpcodecs_vd_drivers[i]->info->comment);
}

static int init_video(sh_video_t *sh_video, char *codecname, char *vfm,
                      int status, stringset_t *selected)
{
    int force = 0;
    unsigned int orig_fourcc = sh_video->bih ? sh_video->bih->biCompression : 0;
    sh_video->codec = NULL;
    sh_video->vf_initialized = 0;
    if (codecname && codecname[0] == '+') {
        codecname = &codecname[1];
        force = 1;
    }

    while (1) {
        int i;
        int orig_w, orig_h;
        // restore original fourcc:
        if (sh_video->bih)
            sh_video->bih->biCompression = orig_fourcc;
        if (!(sh_video->codec =
              find_video_codec(sh_video->format,
                               sh_video->bih ? ((unsigned int *) &sh_video->bih->biCompression) : NULL,
                               sh_video->codec, force)))
            break;
        // ok we found one codec
        if (stringset_test(selected, sh_video->codec->name))
            continue;           // already tried & failed
        if (codecname && strcmp(sh_video->codec->name, codecname))
            continue;           // -vc
        if (vfm && strcmp(sh_video->codec->drv, vfm))
            continue;           // vfm doesn't match
        if (!force && sh_video->codec->status < status)
            continue;           // too unstable
        stringset_add(selected, sh_video->codec->name); // tagging it
        // ok, it matches all rules, let's find the driver!
        for (i = 0; mpcodecs_vd_drivers[i] != NULL; i++)
//          if(mpcodecs_vd_drivers[i]->info->id==sh_video->codec->driver) break;
            if (!strcmp
                (mpcodecs_vd_drivers[i]->info->short_name,
                 sh_video->codec->drv))
                break;
        mpvdec = mpcodecs_vd_drivers[i];
#ifdef CONFIG_DYNAMIC_PLUGINS
        if (!mpvdec) {
            /* try to open shared decoder plugin */
            int buf_len;
            char *buf;
            vd_functions_t *funcs_sym;
            vd_info_t *info_sym;

            buf_len = strlen(MPLAYER_LIBDIR) +
                      strlen(sh_video->codec->drv) + 16;
            buf = malloc(buf_len);
            if (!buf)
                break;
            snprintf(buf, buf_len, "%s/mplayer/vd_%s.so", MPLAYER_LIBDIR,
                     sh_video->codec->drv);
            mp_msg(MSGT_DECVIDEO, MSGL_DBG2,
                   "Trying to open external plugin: %s\n", buf);
            sh_video->dec_handle = dlopen(buf, RTLD_LAZY);
            if (!sh_video->dec_handle)
                break;
            snprintf(buf, buf_len, "mpcodecs_vd_%s", sh_video->codec->drv);
            funcs_sym = dlsym(sh_video->dec_handle, buf);
            if (!funcs_sym || !funcs_sym->info || !funcs_sym->init
                || !funcs_sym->uninit || !funcs_sym->control
                || !funcs_sym->decode)
                break;
            info_sym = funcs_sym->info;
            if (strcmp(info_sym->short_name, sh_video->codec->drv))
                break;
            free(buf);
            mpvdec = funcs_sym;
            mp_msg(MSGT_DECVIDEO, MSGL_V,
                   "Using external decoder plugin (%s/mplayer/vd_%s.so)!\n",
                   MPLAYER_LIBDIR, sh_video->codec->drv);
        }
#endif
        if (!mpvdec) {          // driver not available (==compiled in)
            mp_msg(MSGT_DECVIDEO, MSGL_WARN,
                   MSGTR_VideoCodecFamilyNotAvailableStr,
                   sh_video->codec->name, sh_video->codec->drv);
            continue;
        }
        /* only allow dummy codecs if specified via -vc */
        if (sh_video->codec->flags & CODECS_FLAG_DUMMY && !codecname) {
            continue;
        }

        orig_w = sh_video->bih ? sh_video->bih->biWidth  : sh_video->disp_w;
        orig_h = sh_video->bih ? sh_video->bih->biHeight : sh_video->disp_h;
        sh_video->disp_w = orig_w;
        sh_video->disp_h = orig_h;
        // it's available, let's try to init!
        if (sh_video->codec->flags & CODECS_FLAG_ALIGN16) {
            // align width/height to n*16
            sh_video->disp_w = (sh_video->disp_w + 15) & (~15);
            sh_video->disp_h = (sh_video->disp_h + 15) & (~15);
        }
        if (sh_video->bih) {
            sh_video->bih->biWidth  = sh_video->disp_w;
            sh_video->bih->biHeight = sh_video->disp_h;
        }
        // init()
        mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_OpeningVideoDecoder,
               mpvdec->info->short_name, mpvdec->info->name);
        // clear vf init error, it is no longer relevant
        if (sh_video->vf_initialized < 0)
            sh_video->vf_initialized = 0;
        if (!mpvdec->init(sh_video)) {
            mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_VDecoderInitFailed);
            sh_video->disp_w = orig_w;
            sh_video->disp_h = orig_h;
            if (sh_video->bih) {
                sh_video->bih->biWidth  = sh_video->disp_w;
                sh_video->bih->biHeight = sh_video->disp_h;
            }
            continue;           // try next...
        }
        // Yeah! We got it!
        sh_video->initialized = 1;
        return 1;
    }
    return 0;
}

int init_best_video_codec(sh_video_t *sh_video, char **video_codec_list,
                          char **video_fm_list)
{
    char *vc_l_default[2] = { "", (char *) NULL };
    stringset_t selected;
    // hack:
    if (!video_codec_list)
        video_codec_list = vc_l_default;
    // Go through the codec.conf and find the best codec...
    sh_video->initialized = 0;
    stringset_init(&selected);
    while (!sh_video->initialized && *video_codec_list) {
        char *video_codec = *(video_codec_list++);
        if (video_codec[0]) {
            if (video_codec[0] == '-') {
                // disable this codec:
                stringset_add(&selected, video_codec + 1);
            } else {
                // forced codec by name:
                mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_ForcedVideoCodec,
                       video_codec);
                init_video(sh_video, video_codec, NULL, -1, &selected);
            }
        } else {
            int status;
            // try in stability order: UNTESTED, WORKING, BUGGY. never try CRASHING.
            if (video_fm_list) {
                char **fmlist = video_fm_list;
                // try first the preferred codec families:
                while (!sh_video->initialized && *fmlist) {
                    char *video_fm = *(fmlist++);
                    mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_TryForceVideoFmtStr,
                           video_fm);
                    for (status = CODECS_STATUS__MAX;
                         status >= CODECS_STATUS__MIN; --status)
                        if (init_video
                            (sh_video, NULL, video_fm, status, &selected))
                            break;
                }
            }
            if (!sh_video->initialized)
                for (status = CODECS_STATUS__MAX; status >= CODECS_STATUS__MIN;
                     --status)
                    if (init_video(sh_video, NULL, NULL, status, &selected))
                        break;
        }
    }
    stringset_free(&selected);

    if (!sh_video->initialized) {
        mp_msg(MSGT_DECVIDEO, MSGL_ERR, MSGTR_CantFindVideoCodec,
               sh_video->format);
        return 0;               // failed
    }

    mp_msg(MSGT_DECVIDEO, MSGL_INFO, MSGTR_SelectedVideoCodec,
           sh_video->codec->name, sh_video->codec->drv, sh_video->codec->info);
    return 1;                   // success
}

void *decode_video(sh_video_t *sh_video, unsigned char *start, int in_size,
                   int drop_frame, double pts, int *full_frame)
{
    mp_image_t *mpi = NULL;
    unsigned int t = GetTimer();
    unsigned int t2;
    double tt;
    int delay;
    int got_picture = 1;

    mpi = mpvdec->decode(sh_video, start, in_size, drop_frame);

    //------------------------ frame decoded. --------------------

    if (mpi && mpi->type == MP_IMGTYPE_INCOMPLETE) {
    got_picture = 0;
    mpi = NULL;
    }

    if (full_frame)
    *full_frame = got_picture;

    delay = get_current_video_decoder_lag(sh_video);
    if (correct_pts && pts != MP_NOPTS_VALUE
        && (got_picture || sh_video->num_buffered_pts < delay)) {
        if (sh_video->num_buffered_pts ==
            sizeof(sh_video->buffered_pts) / sizeof(double))
            mp_msg(MSGT_DECVIDEO, MSGL_ERR, "Too many buffered pts\n");
        else {
            int i, j;
            for (i = 0; i < sh_video->num_buffered_pts; i++)
                if (sh_video->buffered_pts[i] < pts)
                    break;
            for (j = sh_video->num_buffered_pts; j > i; j--)
                sh_video->buffered_pts[j] = sh_video->buffered_pts[j - 1];
            sh_video->buffered_pts[i] = pts;
            sh_video->num_buffered_pts++;
        }
    }

    // some codecs are broken, and doesn't restore MMX state :(
    // it happens usually with broken/damaged files.
    if (HAVE_AMD3DNOW && gCpuCaps.has3DNow) {
        __asm__ volatile ("femms\n\t":::"memory");
    } else if (HAVE_MMX && gCpuCaps.hasMMX) {
        __asm__ volatile ("emms\n\t":::"memory");
    }

    t2 = GetTimer();
    t = t2 - t;
    tt = t * 0.000001f;
    video_time_usage += tt;

    if (!mpi || drop_frame)
        return NULL;            // error / skipped frame

    if (field_dominance == 0)
        mpi->fields |= MP_IMGFIELD_TOP_FIRST;
    else if (field_dominance == 1)
        mpi->fields &= ~MP_IMGFIELD_TOP_FIRST;

    if (correct_pts) {
        if (sh_video->num_buffered_pts) {
            sh_video->num_buffered_pts--;
            sh_video->pts = sh_video->buffered_pts[sh_video->num_buffered_pts];
        } else {
            mp_msg(MSGT_CPLAYER, MSGL_ERR,
                   "No pts value from demuxer to use for frame!\n");
            sh_video->pts = MP_NOPTS_VALUE;
        }
        if (delay >= 0) {
            // limit buffered pts only afterwards so we do not get confused
            // by packets that produce no output (e.g. a single field of a
            // H.264 frame).
            if (delay > sh_video->num_buffered_pts)
#if 0
                // this is disabled because vd_ffmpeg reports the same lag
                // after seek even when there are no buffered frames,
                // leading to incorrect error messages
                mp_msg(MSGT_DECVIDEO, MSGL_ERR, "Not enough buffered pts\n");
#else
                ;
#endif
            else
                sh_video->num_buffered_pts = delay;
        }
    }
    return mpi;
}

int filter_video(sh_video_t *sh_video, void *frame, double pts)
{
    mp_image_t *mpi = frame;
    unsigned int t2 = GetTimer();
    vf_instance_t *vf = sh_video->vfilter;
    // apply video filters and call the leaf vo/ve
    int ret = vf->put_image(vf, mpi, pts);
    if (ret > 0) {
        // draw EOSD first so it ends up below the OSD.
        // Note that changing this is will not work right with vf_ass and the
        // vos currently always draw the EOSD first in paused mode.
#ifdef CONFIG_ASS
        vf->control(vf, VFCTRL_DRAW_EOSD, NULL);
#endif
        vf->control(vf, VFCTRL_DRAW_OSD, NULL);
    }

    t2 = GetTimer() - t2;
    vout_time_usage += t2 * 0.000001;

    return ret;
}

Ах, кодек, пишеться з буквою Е, між іншим.