FFmpeg/libavformat/avisynth.c

/*
 * AviSynth support
 * Copyright (c) 2006 DivX, Inc.
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <windows.h>
#include <vfw.h>

#include "libavutil/internal.h"
#include "avformat.h"
#include "internal.h"
#include "riff.h"

typedef struct {
    PAVISTREAM handle;
    AVISTREAMINFO info;
    DWORD read;
    LONG chunck_size;
    LONG chunck_samples;
} AviSynthStream;

typedef struct {
    PAVIFILE file;
    AviSynthStream *streams;
    int nb_streams;
    int next_stream;
} AviSynthContext;

static int avisynth_read_header(AVFormatContext *s)
{
    AviSynthContext *avs = s->priv_data;
    HRESULT res;
    AVIFILEINFO info;
    DWORD id;
    AVStream *st;
    AviSynthStream *stream;
    wchar_t filename_wchar[1024] = { 0 };
    char filename_char[1024]     = { 0 };

    AVIFileInit();

    /* AviSynth cannot accept UTF-8 file names. */
    MultiByteToWideChar(CP_UTF8, 0, s->filename, -1, filename_wchar, 1024);
    WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wchar, -1, filename_char,
                        1024, NULL, NULL);
    res = AVIFileOpen(&avs->file, filename_char,
                      OF_READ | OF_SHARE_DENY_WRITE, NULL);
    if (res != S_OK) {
        av_log(s, AV_LOG_ERROR, "AVIFileOpen failed with error %ld", res);
        AVIFileExit();
        return -1;
    }

    res = AVIFileInfo(avs->file, &info, sizeof(info));
    if (res != S_OK) {
        av_log(s, AV_LOG_ERROR, "AVIFileInfo failed with error %ld", res);
        AVIFileExit();
        return -1;
    }

    avs->streams = av_mallocz(info.dwStreams * sizeof(AviSynthStream));

    for (id = 0; id < info.dwStreams; id++) {
        stream       = &avs->streams[id];
        stream->read = 0;
        if (AVIFileGetStream(avs->file, &stream->handle, 0, id) == S_OK &&
            AVIStreamInfo(stream->handle, &stream->info,
                          sizeof(stream->info)) == S_OK) {
            if (stream->info.fccType == streamtypeAUDIO) {
                WAVEFORMATEX wvfmt;
                LONG struct_size = sizeof(WAVEFORMATEX);
                if (AVIStreamReadFormat(stream->handle, 0,
                                        &wvfmt, &struct_size) != S_OK)
                    continue;

                st                    = avformat_new_stream(s, NULL);
                st->id                = id;
                st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

                st->codec->block_align           = wvfmt.nBlockAlign;
                st->codec->channels              = wvfmt.nChannels;
                st->codec->sample_rate           = wvfmt.nSamplesPerSec;
                st->codec->bit_rate              = wvfmt.nAvgBytesPerSec * 8;
                st->codec->bits_per_coded_sample = wvfmt.wBitsPerSample;

                stream->chunck_samples = wvfmt.nSamplesPerSec *
                                         (uint64_t)info.dwScale /
                                         (uint64_t)info.dwRate;
                stream->chunck_size    = stream->chunck_samples *
                                         wvfmt.nChannels *
                                         wvfmt.wBitsPerSample / 8;

                st->codec->codec_tag = wvfmt.wFormatTag;
                st->codec->codec_id  =
                    ff_wav_codec_get_id(wvfmt.wFormatTag,
                                        st->codec->bits_per_coded_sample);
            } else if (stream->info.fccType == streamtypeVIDEO) {
                BITMAPINFO imgfmt;
                LONG struct_size = sizeof(BITMAPINFO);

                stream->chunck_size    = stream->info.dwSampleSize;
                stream->chunck_samples = 1;

                if (AVIStreamReadFormat(stream->handle, 0, &imgfmt,
                                        &struct_size) != S_OK)
                    continue;

                st                     = avformat_new_stream(s, NULL);
                st->id                 = id;
                st->codec->codec_type  = AVMEDIA_TYPE_VIDEO;
                st->avg_frame_rate.num = stream->info.dwRate;
                st->avg_frame_rate.den = stream->info.dwScale;

                st->codec->width  = imgfmt.bmiHeader.biWidth;
                st->codec->height = imgfmt.bmiHeader.biHeight;

                st->codec->bits_per_coded_sample = imgfmt.bmiHeader.biBitCount;
                st->codec->bit_rate              = (uint64_t)stream->info.dwSampleSize *
                                                   (uint64_t)stream->info.dwRate * 8 /
                                                   (uint64_t)stream->info.dwScale;
                st->codec->codec_tag             = imgfmt.bmiHeader.biCompression;
                st->codec->codec_id              =
                    ff_codec_get_id(ff_codec_bmp_tags,
                                    imgfmt.bmiHeader.biCompression);

                st->duration = stream->info.dwLength;
            } else {
                AVIStreamRelease(stream->handle);
                continue;
            }

            avs->nb_streams++;

            st->codec->stream_codec_tag = stream->info.fccHandler;

            avpriv_set_pts_info(st, 64, info.dwScale, info.dwRate);
            st->start_time = stream->info.dwStart;
        }
    }

    return 0;
}

static int avisynth_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AviSynthContext *avs = s->priv_data;
    HRESULT res;
    AviSynthStream *stream;
    int stream_id = avs->next_stream;
    LONG read_size;

    // handle interleaving manually...
    stream = &avs->streams[stream_id];

    if (stream->read >= stream->info.dwLength)
        return AVERROR(EIO);

    if (av_new_packet(pkt, stream->chunck_size))
        return AVERROR(EIO);
    pkt->stream_index = stream_id;
    pkt->pts          = avs->streams[stream_id].read /
                        avs->streams[stream_id].chunck_samples;

    res = AVIStreamRead(stream->handle, stream->read, stream->chunck_samples,
                        pkt->data, stream->chunck_size, &read_size, NULL);

    pkt->pts  = stream->read;
    pkt->size = read_size;

    stream->read += stream->chunck_samples;

    // prepare for the next stream to read
    do
        avs->next_stream = (avs->next_stream + 1) % avs->nb_streams;
    while (avs->next_stream != stream_id &&
           s->streams[avs->next_stream]->discard >= AVDISCARD_ALL);

    return (res == S_OK) ? pkt->size : -1;
}

static int avisynth_read_close(AVFormatContext *s)
{
    AviSynthContext *avs = s->priv_data;
    int i;

    for (i = 0; i < avs->nb_streams; i++)
        AVIStreamRelease(avs->streams[i].handle);

    av_free(avs->streams);
    AVIFileRelease(avs->file);
    AVIFileExit();
    return 0;
}

static int avisynth_read_seek(AVFormatContext *s, int stream_index,
                              int64_t pts, int flags)
{
    AviSynthContext *avs = s->priv_data;
    int stream_id;

    for (stream_id = 0; stream_id < avs->nb_streams; stream_id++)
        avs->streams[stream_id].read =
            pts * avs->streams[stream_id].chunck_samples;

    return 0;
}

AVInputFormat ff_avisynth_demuxer = {
    .name           = "avisynth",
    .long_name      = NULL_IF_CONFIG_SMALL("AviSynth"),
    .priv_data_size = sizeof(AviSynthContext),
    .read_header    = avisynth_read_header,
    .read_packet    = avisynth_read_packet,
    .read_close     = avisynth_read_close,
    .read_seek      = avisynth_read_seek,
    .extensions     = "avs",
};