[FFmpeg-devel] [PATCH 1/2] avformat: add binka demuxer

[Andreas Rheinhardt]

Paul B Mahol:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavformat/Makefile     |   1 +
>  libavformat/allformats.c |   1 +
>  libavformat/binka.c      | 107 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 109 insertions(+)
>  create mode 100644 libavformat/binka.c
> 
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index 85f432c8d9..b977fa0b1e 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -131,6 +131,7 @@ OBJS-$(CONFIG_AVS3_DEMUXER)              += avs3dec.o rawdec.o
>  OBJS-$(CONFIG_BETHSOFTVID_DEMUXER)       += bethsoftvid.o
>  OBJS-$(CONFIG_BFI_DEMUXER)               += bfi.o
>  OBJS-$(CONFIG_BINK_DEMUXER)              += bink.o
> +OBJS-$(CONFIG_BINKA_DEMUXER)             += binka.o
>  OBJS-$(CONFIG_BINTEXT_DEMUXER)           += bintext.o sauce.o
>  OBJS-$(CONFIG_BIT_DEMUXER)               += bit.o
>  OBJS-$(CONFIG_BIT_MUXER)                 += bit.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 6990af55f4..9628c726a7 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -94,6 +94,7 @@ extern AVInputFormat  ff_bethsoftvid_demuxer;
>  extern AVInputFormat  ff_bfi_demuxer;
>  extern AVInputFormat  ff_bintext_demuxer;
>  extern AVInputFormat  ff_bink_demuxer;
> +extern AVInputFormat  ff_binka_demuxer;
>  extern AVInputFormat  ff_bit_demuxer;
>  extern AVOutputFormat ff_bit_muxer;
>  extern AVInputFormat  ff_bmv_demuxer;
> diff --git a/libavformat/binka.c b/libavformat/binka.c
> new file mode 100644
> index 0000000000..5ed0f17968
> --- /dev/null
> +++ b/libavformat/binka.c
> @@ -0,0 +1,107 @@
> +/*
> + * Copyright (c) 2021 Paul B Mahol
> + *
> + * 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/intreadwrite.h"
> +#include "avformat.h"
> +#include "internal.h"
> +
> +static int binka_probe(const AVProbeData *p)
> +{
> +    if (AV_RB32(p->buf) == MKBETAG('1', 'F', 'C', 'B'))
> +        return AVPROBE_SCORE_MAX;
> +    return 0;
> +}
> +
> +static int binka_read_header(AVFormatContext *s)
> +{
> +    AVIOContext *pb = s->pb;
> +    AVStream *st;
> +    uint32_t samples;
> +    int entries;
> +    int64_t offset;
> +    int ret;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    avio_skip(pb, 5);
> +
> +    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
> +    st->codecpar->codec_id = AV_CODEC_ID_BINKAUDIO_DCT;
> +    st->codecpar->channels = avio_r8(pb);
> +    st->codecpar->sample_rate = avio_rl16(pb);
> +    st->duration = avio_rl32(pb);
> +
> +    avio_skip(pb, 4);
> +    samples = avio_rl32(pb);

This should lead to unused-but-set warnings. Better skip eight bytes at
once and remove it (you can add a comment describing what it is (and do
you know what the other bytes you are skipping are for?)).

> +    entries = avio_rl16(pb);
> +
> +    if ((ret = ff_get_extradata(s, st->codecpar, pb, 2)) < 0)
> +        return ret;
> +
> +    offset = entries * 2;
> +    avio_skip(pb, offset);
> +
> +    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
> +
> +    s->internal->data_offset = avio_tell(pb);

This is already done generically.

> +
> +    return 0;
> +}
> +
> +static int binka_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    AVIOContext *pb = s->pb;
> +    int64_t pos;
> +    int pkt_size;
> +    int ret;
> +
> +    if (avio_feof(pb))
> +        return AVERROR_EOF;
> +
> +    pos = avio_tell(pb);
> +    avio_skip(pb, 2);
> +    pkt_size = avio_rl16(pb) + 4;
> +    if (pkt_size <= 4)
> +        return AVERROR(EIO);
> +    ret = av_new_packet(pkt, pkt_size);
> +    if (ret < 0)
> +        return ret;
> +
> +    avio_read(pb, pkt->data + 4, pkt_size - 4);
> +    AV_WL32(pkt->data, pkt_size);
> +
> +    pkt->pos = pos;
> +    pkt->stream_index = 0;
> +    pkt->flags |= AV_PKT_FLAG_KEY;
> +
> +    return 0;
> +}
> +
> +AVInputFormat ff_binka_demuxer = {
> +    .name           = "binka",
> +    .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio"),
> +    .read_probe     = binka_probe,
> +    .read_header    = binka_read_header,
> +    .read_packet    = binka_read_packet,
> +    .flags          = AVFMT_GENERIC_INDEX,
> +    .extensions     = "binka",
> +};
>