[FFmpeg-devel] [PATCH] avformat/aea: Add aea muxer

[Andreas Rheinhardt]

asivery via ffmpeg-devel:
> +#include "libavutil/intreadwrite.h"
> +#include "libavutil/avstring.h"

These two headers seem unused.

> +#include "avformat.h"
> +#include "avio_internal.h"
> +#include "rawenc.h"
> +#include "mux.h"
> +
> +static int aea_write_header(AVFormatContext *s)
> +{
> +    const AVDictionaryEntry *title_entry;
> +    int title_length = 0;
> +    char* title_contents;

const please. Also we put the * to the variable (because "char* foo,
bar" still only declares one pointer to char). Furthermore, the scope
for this should be the block below.

> +    AVStream *st;
> +
> +    if (s->nb_streams > 1) {
> +        av_log(s, AV_LOG_WARNING, "Got more than one stream to encode. This is not supported.\n");
> +        return AVERROR(EINVAL);
> +    }
> +    
> +    st = s->streams[0];
> +    if (st->codecpar->ch_layout.nb_channels != 1 && st->codecpar->ch_layout.nb_channels != 2) {
> +        av_log(s, AV_LOG_ERROR, "Invalid amount of channels to mux (%d).\n", st->codecpar->ch_layout.nb_channels);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    if (st->codecpar->sample_rate != 44100) {
> +        av_log(s, AV_LOG_ERROR, "Invalid sample rate (%d) AEA only supports 44.1kHz.\n", st->codecpar->sample_rate);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    /* Write magic */
> +    avio_wl32(s->pb, 2048);
> +    
> +    /* Write AEA title */
> +    title_entry = av_dict_get(st->metadata, "title", NULL, 0);
> +    if (title_entry) {
> +        title_contents = title_entry->value;
> +        title_length = strlen(title_contents);

Possible truncation here.

> +        title_length = FFMIN(256, title_length);
> +        avio_write(s->pb, title_contents, title_length);
> +    }
> +
> +    ffio_fill(s->pb, 0, 256 - title_length);
> +
> +    /* Write number of frames (zero at header-writing time, will seek later), number of channels */
> +    avio_wl32(s->pb, 0);
> +    avio_w8(s->pb, st->codecpar->ch_layout.nb_channels);
> +    avio_w8(s->pb, 0);
> +
> +    /* Pad the header to 2048 bytes */
> +    ffio_fill(s->pb, 0, 1782);
> +
> +    return 0;
> +}
> +
> +static int aea_write_trailer(struct AVFormatContext *s)
> +{
> +    AVIOContext *pb = s->pb;
> +    AVStream *st = s->streams[0];
> +    if (pb->seekable & AVIO_SEEKABLE_NORMAL) {
> +        /* Seek to rewrite the block count. */
> +        avio_seek(pb, 260, SEEK_SET);
> +        avio_wl32(pb, st->nb_frames * st->codecpar->ch_layout.nb_channels);

I don't see anything guaranteeing that the result fits into 32 bits.

> +    } else {
> +        av_log(s, AV_LOG_WARNING, "unable to rewrite AEA header.\n");
> +    }
> +
> +    return 0;
> +}
> +
> +const FFOutputFormat ff_aea_muxer = {
> +    .p.name           = "aea",
> +    .p.long_name      = NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
> +    .p.extensions     = "aea",
> +    .p.audio_codec    = AV_CODEC_ID_ATRAC1,
> +
> +    .write_header     = aea_write_header,
> +    .write_packet     = ff_raw_write_packet,
> +    .write_trailer    = aea_write_trailer,
> +};