FFmpeg/libavfilter/buffer.c

/*
 * Copyright Stefano Sabatini <stefasab gmail com>
 * Copyright Anton Khirnov <anton khirnov net>
 * Copyright Michael Niedermayer <michaelni gmx at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg 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.
 *
 * FFmpeg 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 FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/channel_layout.h"
#include "libavutil/avassert.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavcodec/avcodec.h"

#include "avfilter.h"
#include "internal.h"
#include "audio.h"
#include "avcodec.h"

void ff_avfilter_default_free_buffer(AVFilterBuffer *ptr)
{
    if (ptr->extended_data != ptr->data)
        av_freep(&ptr->extended_data);
    av_free(ptr->data[0]);
    av_free(ptr);
}

static void copy_video_props(AVFilterBufferRefVideoProps *dst, AVFilterBufferRefVideoProps *src) {
    *dst = *src;
    if (src->qp_table) {
        int qsize = src->qp_table_size;
        dst->qp_table = av_malloc(qsize);
        memcpy(dst->qp_table, src->qp_table, qsize);
    }
}

AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)
{
    AVFilterBufferRef *ret = av_malloc(sizeof(AVFilterBufferRef));
    if (!ret)
        return NULL;
    *ret = *ref;

    ret->metadata = NULL;
    av_dict_copy(&ret->metadata, ref->metadata, 0);

    if (ref->type == AVMEDIA_TYPE_VIDEO) {
        ret->video = av_malloc(sizeof(AVFilterBufferRefVideoProps));
        if (!ret->video) {
            av_free(ret);
            return NULL;
        }
        copy_video_props(ret->video, ref->video);
        ret->extended_data = ret->data;
    } else if (ref->type == AVMEDIA_TYPE_AUDIO) {
        ret->audio = av_malloc(sizeof(AVFilterBufferRefAudioProps));
        if (!ret->audio) {
            av_free(ret);
            return NULL;
        }
        *ret->audio = *ref->audio;

        if (ref->extended_data && ref->extended_data != ref->data) {
            int nb_channels = av_get_channel_layout_nb_channels(ref->audio->channel_layout);
            if (!(ret->extended_data = av_malloc(sizeof(*ret->extended_data) *
                                                 nb_channels))) {
                av_freep(&ret->audio);
                av_freep(&ret);
                return NULL;
            }
            memcpy(ret->extended_data, ref->extended_data,
                   sizeof(*ret->extended_data) * nb_channels);
        } else
            ret->extended_data = ret->data;
    }
    ret->perms &= pmask;
    ret->buf->refcount ++;
    return ret;
}

void ff_free_pool(AVFilterPool *pool)
{
    int i;

    av_assert0(pool->refcount > 0);

    for (i = 0; i < POOL_SIZE; i++) {
        if (pool->pic[i]) {
            AVFilterBufferRef *picref = pool->pic[i];
            /* free buffer: picrefs stored in the pool are not
             * supposed to contain a free callback */
            av_assert0(!picref->buf->refcount);
            av_freep(&picref->buf->data[0]);
            av_freep(&picref->buf);

            av_freep(&picref->audio);
            av_assert0(!picref->video || !picref->video->qp_table);
            av_freep(&picref->video);
            av_freep(&pool->pic[i]);
            pool->count--;
        }
    }
    pool->draining = 1;

    if (!--pool->refcount) {
        av_assert0(!pool->count);
        av_free(pool);
    }
}

static void store_in_pool(AVFilterBufferRef *ref)
{
    int i;
    AVFilterPool *pool= ref->buf->priv;

    av_assert0(ref->buf->data[0]);
    av_assert0(pool->refcount>0);

    if (ref->video)
        av_freep(&ref->video->qp_table);

    if (pool->count == POOL_SIZE) {
        AVFilterBufferRef *ref1 = pool->pic[0];
        av_freep(&ref1->video);
        av_freep(&ref1->audio);
        av_freep(&ref1->buf->data[0]);
        av_freep(&ref1->buf);
        av_free(ref1);
        memmove(&pool->pic[0], &pool->pic[1], sizeof(void*)*(POOL_SIZE-1));
        pool->count--;
        pool->pic[POOL_SIZE-1] = NULL;
    }

    for (i = 0; i < POOL_SIZE; i++) {
        if (!pool->pic[i]) {
            pool->pic[i] = ref;
            pool->count++;
            break;
        }
    }
    if (pool->draining) {
        ff_free_pool(pool);
    } else
        --pool->refcount;
}

void avfilter_unref_buffer(AVFilterBufferRef *ref)
{
    if (!ref)
        return;
    av_assert0(ref->buf->refcount > 0);
    if (!(--ref->buf->refcount)) {
        if (!ref->buf->free) {
            store_in_pool(ref);
            return;
        }
        ref->buf->free(ref->buf);
    }
    if (ref->extended_data != ref->data)
        av_freep(&ref->extended_data);
    if (ref->video)
        av_freep(&ref->video->qp_table);
    av_freep(&ref->video);
    av_freep(&ref->audio);
    av_dict_free(&ref->metadata);
    av_free(ref);
}

void avfilter_unref_bufferp(AVFilterBufferRef **ref)
{
    avfilter_unref_buffer(*ref);
    *ref = NULL;
}

void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, AVFilterBufferRef *src)
{
    // copy common properties
    dst->pts             = src->pts;
    dst->pos             = src->pos;

    switch (src->type) {
    case AVMEDIA_TYPE_VIDEO: {
        if (dst->video->qp_table)
            av_freep(&dst->video->qp_table);
        copy_video_props(dst->video, src->video);
        break;
    }
    case AVMEDIA_TYPE_AUDIO: *dst->audio = *src->audio; break;
    default: break;
    }

    av_dict_free(&dst->metadata);
    av_dict_copy(&dst->metadata, src->metadata, 0);
}

AVFilterBufferRef *ff_copy_buffer_ref(AVFilterLink *outlink,
                                      AVFilterBufferRef *ref)
{
    AVFilterBufferRef *buf;
    int channels;

    switch (outlink->type) {

    case AVMEDIA_TYPE_VIDEO:
        buf = ff_get_video_buffer(outlink, AV_PERM_WRITE,
                                  ref->video->w, ref->video->h);
        if(!buf)
            return NULL;
        av_image_copy(buf->data, buf->linesize,
                      (void*)ref->data, ref->linesize,
                      ref->format, ref->video->w, ref->video->h);
        break;

    case AVMEDIA_TYPE_AUDIO:
        buf = ff_get_audio_buffer(outlink, AV_PERM_WRITE,
                                        ref->audio->nb_samples);
        if(!buf)
            return NULL;
        channels = ref->audio->channels;
        av_samples_copy(buf->extended_data, ref->buf->extended_data,
                        0, 0, ref->audio->nb_samples,
                        channels,
                        ref->format);
        break;

    default:
        return NULL;
    }
    avfilter_copy_buffer_ref_props(buf, ref);
    return buf;
}