mpv/common/av_log.c

/*
 * av_log to mp_msg converter
 * Copyright (C) 2006 Michael Niedermayer
 * Copyright (C) 2009 Uoti Urpala
 *
 * This file is part of mpv.
 *
 * mpv 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.
 *
 * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <pthread.h>

#include "av_log.h"
#include "config.h"
#include "common/common.h"
#include "common/global.h"
#include "common/msg.h"

#include <libavutil/avutil.h>
#include <libavutil/log.h>

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

#if HAVE_LIBAVDEVICE
#include <libavdevice/avdevice.h>
#endif

#if HAVE_LIBAVFILTER
#include <libavfilter/avfilter.h>
#endif

#if HAVE_LIBAVRESAMPLE
#include <libavresample/avresample.h>
#endif
#if HAVE_LIBSWRESAMPLE
#include <libswresample/swresample.h>
#endif

#if LIBAVCODEC_VERSION_MICRO >= 100
#define LIB_PREFIX "ffmpeg"
#else
#define LIB_PREFIX "libav"
#endif

// Needed because the av_log callback does not provide a library-safe message
// callback.
static pthread_mutex_t log_lock = PTHREAD_MUTEX_INITIALIZER;
static struct mpv_global *log_mpv_instance;
static struct mp_log *log_root, *log_decaudio, *log_decvideo, *log_demuxer;
static bool log_print_prefix = true;

static int av_log_level_to_mp_level(int av_level)
{
    if (av_level > AV_LOG_VERBOSE)
        return MSGL_DEBUG;
    if (av_level > AV_LOG_INFO)
        return MSGL_V;
    if (av_level > AV_LOG_WARNING)
        return MSGL_V;
    if (av_level > AV_LOG_ERROR)
        return MSGL_WARN;
    if (av_level > AV_LOG_FATAL)
        return MSGL_ERR;
    return MSGL_FATAL;
}

static struct mp_log *get_av_log(void *ptr)
{
    if (!ptr)
        return log_root;

    AVClass *avc = *(AVClass **)ptr;
    if (!avc) {
        mp_warn(log_root,
               "av_log callback called with bad parameters (NULL AVClass).\n"
               "This is a bug in one of Libav/FFmpeg libraries used.\n");
        return log_root;
    }

    if (!strcmp(avc->class_name, "AVCodecContext")) {
        AVCodecContext *s = ptr;
        if (s->codec) {
            if (s->codec->type == AVMEDIA_TYPE_AUDIO) {
                if (s->codec->decode)
                    return log_decaudio;
            } else if (s->codec->type == AVMEDIA_TYPE_VIDEO) {
                if (s->codec->decode)
                    return log_decvideo;
            }
        }
    }

    if (!strcmp(avc->class_name, "AVFormatContext")) {
        AVFormatContext *s = ptr;
        if (s->iformat)
            return log_demuxer;
    }

    return log_root;
}

static void mp_msg_av_log_callback(void *ptr, int level, const char *fmt,
                                   va_list vl)
{
    AVClass *avc = ptr ? *(AVClass **)ptr : NULL;
    int mp_level = av_log_level_to_mp_level(level);

    // Note: mp_log is thread-safe, but destruction of the log instances is not.
    pthread_mutex_lock(&log_lock);

    if (!log_mpv_instance) {
        pthread_mutex_unlock(&log_lock);
        // Fallback to stderr
        vfprintf(stderr, fmt, vl);
        return;
    }

    struct mp_log *log = get_av_log(ptr);

    if (mp_msg_test(log, mp_level)) {
        const char *prefix = avc ? avc->item_name(ptr) : NULL;
        if (log_print_prefix && prefix)
            mp_msg(log, mp_level, "%s: ", prefix);
        log_print_prefix = fmt[strlen(fmt) - 1] == '\n';

        mp_msg_va(log, mp_level, fmt, vl);
    }

    pthread_mutex_unlock(&log_lock);
}

void init_libav(struct mpv_global *global)
{
    pthread_mutex_lock(&log_lock);
    if (!log_mpv_instance) {
        log_mpv_instance = global;
        log_root = mp_log_new(NULL, global->log, LIB_PREFIX);
        log_decaudio = mp_log_new(log_root, log_root, "audio");
        log_decvideo = mp_log_new(log_root, log_root, "video");
        log_demuxer = mp_log_new(log_root, log_root, "demuxer");
        av_log_set_callback(mp_msg_av_log_callback);
    }
    pthread_mutex_unlock(&log_lock);

    avcodec_register_all();
    av_register_all();
    avformat_network_init();

#if HAVE_LIBAVFILTER
    avfilter_register_all();
#endif
#if HAVE_LIBAVDEVICE
    avdevice_register_all();
#endif
}

void uninit_libav(struct mpv_global *global)
{
    pthread_mutex_lock(&log_lock);
    if (log_mpv_instance == global) {
        av_log_set_callback(av_log_default_callback);
        log_mpv_instance = NULL;
        talloc_free(log_root);
    }
    pthread_mutex_unlock(&log_lock);
}

#define V(x) (x)>>16, (x)>>8 & 255, (x) & 255

struct lib {
    const char *name;
    unsigned buildv;
    unsigned runv;
};

void print_libav_versions(struct mp_log *log, int v)
{
    const struct lib libs[] = {
        {"libavutil",     LIBAVUTIL_VERSION_INT,     avutil_version()},
        {"libavcodec",    LIBAVCODEC_VERSION_INT,    avcodec_version()},
        {"libavformat",   LIBAVFORMAT_VERSION_INT,   avformat_version()},
        {"libswscale",    LIBSWSCALE_VERSION_INT,    swscale_version()},
#if HAVE_LIBAVFILTER
        {"libavfilter",   LIBAVFILTER_VERSION_INT,   avfilter_version()},
#endif
#if HAVE_LIBAVRESAMPLE
        {"libavresample", LIBAVRESAMPLE_VERSION_INT, avresample_version()},
#endif
#if HAVE_LIBSWRESAMPLE
        {"libswresample", LIBSWRESAMPLE_VERSION_INT, swresample_version()},
#endif
    };

    mp_msg(log, v, "%s library versions:\n", LIB_PREFIX);

    bool mismatch = false;
    bool broken = false;
    for (int n = 0; n < MP_ARRAY_SIZE(libs); n++) {
        const struct lib *l = &libs[n];
        mp_msg(log, v, "   %-15s %d.%d.%d", l->name, V(l->buildv));
        if (l->buildv != l->runv) {
            mp_msg(log, v, " (runtime %d.%d.%d)", V(l->runv));
            mismatch = true;
            broken |= ((l->buildv & 255) >= 100) != ((l->runv & 255) >= 100);
        }
        mp_msg(log, v, "\n");
    }
    // This just won't work. It's 100% broken.
    if (broken) {
        mp_fatal(log, "mpv was compiled and linked against a mixture of Libav "
                 "and FFmpeg versions. This won't work and will most likely "
                 "crash at some point. Aborting.\n");
        abort();
    }
    // We don't "really" support mismatched libraries, but if you like to
    // suffer, you're free to enjoy the terrible aspects of dynamic linking.
    // In particular, we don't use all these crazy accessors ffmpeg wants us
    // to use in order to be ABI compatible after Libav merges - because that
    // would make our code incompatible to Libav. It's madness.
    if (mismatch) {
        mp_warn(log, "Warning: mpv was compiled against a different version of "
                "%s than the shared\nlibrary it is linked against. This can "
                "expose subtle ABI compatibility issues\nand can lead to "
                "misbehavior and crashes.\n", LIB_PREFIX);
    }
}

#undef V