[FFmpeg-devel] [PATCH] avformat: add NSP demuxer

[Carl Eugen Hoyos]

2017-12-01 17:26 GMT+01:00 Paul B Mahol <onemda at gmail.com>:

> +static int nsp_read_header(AVFormatContext *s)
> +{
> +    int rate = 0, channels = 0;
> +    uint32_t chunk, size;
> +    AVStream *st;
> +    int64_t pos;
> +
> +    avio_skip(s->pb, 12);

I believe you could set the duration here for the
supported interleaved stereo files.

> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    while (!avio_feof(s->pb)) {
> +        chunk = avio_rb32(s->pb);
> +        size  = avio_rl32(s->pb);
> +        pos   = avio_tell(s->pb);
> +
> +        if (chunk == MKBETAG('H', 'D', 'R', '8') ||
> +            chunk == MKBETAG('H', 'E', 'D', 'R')) {
> +            if (size < 32)
> +                return AVERROR_INVALIDDATA;
> +            avio_skip(s->pb, 20);
> +            rate = avio_rl32(s->pb);

> +            avio_skip(s->pb, size - (avio_tell(s->pb) - pos));

Why is this not "skip(pb, size - 32)" (or whatever the correct
constant is)?

> +        } else if (chunk == MKBETAG('N', 'O', 'T', 'E')) {
> +            char value[1024];
> +
> +            avio_get_str(s->pb, size, value, sizeof(value));
> +            av_dict_set(&s->metadata, "Note", value, 0);

Shouldn't this be "comment"?

> +            avio_skip(s->pb, 1);

Should be something like "avio_skip(pb, size & 1);" according
to the description I found.

> +        } else if (chunk == MKBETAG('S', 'D', 'A', 'B')) {
> +            channels = 2;

If I read correctly, you can set STEREO here.

> +            break;

> +        } else if (chunk == MKBETAG('S', 'D', 'A', '_') ||
> +                   chunk == MKBETAG('S', 'D', '_', 'A') ||
> +                   chunk == MKBETAG('S', 'D', '_', '2') ||
> +                   chunk == MKBETAG('S', 'D', '_', '3') ||
> +                   chunk == MKBETAG('S', 'D', '_', '4') ||
> +                   chunk == MKBETAG('S', 'D', '_', '5') ||
> +                   chunk == MKBETAG('S', 'D', '_', '6') ||
> +                   chunk == MKBETAG('S', 'D', '_', '7') ||
> +                   chunk == MKBETAG('S', 'D', '_', '8')) {

Iiuc, in these cases the file is not read correctly.
If this cannot be implemented easily, a warning should
be shown.

Thank you, Carl Eugen