[FFmpeg-devel] [PATCH] Add FITS Decoder

[Michael Niedermayer]

On Wed, Jun 28, 2017 at 07:22:01PM +0530, Paras Chadha wrote:
> Added code to export metadata as frame metadata
> 
> Signed-off-by: Paras Chadha <paraschadha18 at gmail.com>
> -
[...]
> +/**
> + * function reads the fits header and stores the values in FITSDecContext pointed by header
> + * @param avctx - AVCodec context
> + * @param ptr - pointer to pointer to the data
> + * @param header - pointer to the FITSDecContext
> + * @param end - pointer to end of packet
> + * @return 1, if calculated successfully, otherwise AVERROR_INVALIDDATA
> + */
> +static int fits_read_header(AVCodecContext *avctx, const uint8_t **ptr, FITSDecContext * header,
> +                            const uint8_t * end, AVDictionary **meta)
> +{
> +    const uint8_t *ptr8 = *ptr;
> +    int lines_read = 0, i, dim_no, t, data_min_found = 0, data_max_found = 0, ret;
> +    uint64_t size=1;
> +    double d;
> +    AVDictionary *metadata = NULL;
> +    char keyword[10], value[72];
> +
> +    header->blank = LLONG_MIN;
> +    header->bscale = 1.0;
> +    header->bzero = 0;
> +    header->rgb = 0;
> +
> +    if (end - ptr8 < 80)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (sscanf(ptr8, "SIMPLE = %c", &header->simple) == 1) {
> +        if (header->simple == 'F') {
> +            av_log(avctx, AV_LOG_WARNING, "not a standard FITS file\n");
> +            av_dict_set(&metadata, "SIMPLE", "F", 0);
> +        } else if (header->simple != 'T') {
> +            av_log(avctx, AV_LOG_ERROR, "invalid SIMPLE value, SIMPLE = %c\n", header->simple);
> +            return AVERROR_INVALIDDATA;
> +        } else {
> +            av_dict_set(&metadata, "SIMPLE", "T", 0);
> +        }
> +        header->xtension = 0;
> +    } else if (!strncmp(ptr8, "XTENSION= 'IMAGE", 16)) {
> +        header->xtension = 1;
> +        av_dict_set(&metadata, "XTENSION", "'IMAGE   '", 0);
> +    } else {
> +        av_log(avctx, AV_LOG_ERROR, "missing SIMPLE keyword or invalid XTENSION\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    ptr8 += 80;
> +    lines_read++;
> +
> +    if (end - ptr8 < 80)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (sscanf(ptr8, "BITPIX = %d", &header->bitpix) != 1) {
> +        av_log(avctx, AV_LOG_ERROR, "missing BITPIX keyword\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    av_dict_set_int(&metadata, "BITPIX", header->bitpix, 0);
> +    size = abs(header->bitpix) >> 3;
> +    ptr8 += 80;
> +    lines_read++;
> +
> +    if (end - ptr8 < 80)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (sscanf(ptr8, "NAXIS = %d", &header->naxis) != 1) {
> +        av_log(avctx, AV_LOG_ERROR, "missing NAXIS keyword\n");
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (!header->naxis) {
> +        av_log(avctx, AV_LOG_ERROR, "No image data found, NAXIS = %d\n", header->naxis);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    if (header->naxis != 2 && header->naxis != 3) {
> +        av_log(avctx, AV_LOG_ERROR, "unsupported number of dimensions, NAXIS = %d\n", header->naxis);
> +        return AVERROR_INVALIDDATA;
> +    }
> +
> +    av_dict_set_int(&metadata, "NAXIS", header->naxis, 0);
> +    ptr8 += 80;
> +    lines_read++;
> +
> +    for (i = 0; i < header->naxis; i++) {
> +        if (end - ptr8 < 80)
> +            return AVERROR_INVALIDDATA;
> +
> +        if (sscanf(ptr8, "NAXIS%d = %d", &dim_no, &header->naxisn[i]) != 2 || dim_no != i+1) {
> +            av_log(avctx, AV_LOG_ERROR, "missing NAXIS%d keyword\n", i+1);
> +            return AVERROR_INVALIDDATA;
> +        }
> +

> +        sprintf(keyword, "NAXIS%d", dim_no);

snprintf()


[...]
> +static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
> +{
> +    AVFrame *p=data;
> +    const uint8_t *ptr8 = avpkt->data, *end;
> +    int16_t t16;
> +    int32_t t32;
> +    int64_t t64;
> +    float   tflt;
> +    double  tdbl;
> +    int ret, i, j;
> +    uint8_t *dst8;
> +    uint16_t *dst16;
> +    uint32_t *dst32;
> +    uint64_t *dst64, size, r, g, b, a, t;
> +    FITSDecContext * header = avctx->priv_data;
> +
> +    end = ptr8 + avpkt->size;

> +    if (ret = fits_read_header(avctx, &ptr8, header, end, &p->metadata) < 0)

missing ()

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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