On Fri, Apr 03, 2020 at 11:57:56PM +0530, gautamr...@gmail.com wrote:
> From: Gautam Ramakrishnan <gautamr...@gmail.com>
>
> This patch adds functional changes to support the
> PPT marker.
> ---
> libavcodec/jpeg2000dec.c | 88 ++++++++++++++++++++++++++++++++++++----
> 1 file changed, 79 insertions(+), 9 deletions(-)
>
> diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> index 7103cd6ceb..02905b9e49 100644
> --- a/libavcodec/jpeg2000dec.c
> +++ b/libavcodec/jpeg2000dec.c
> @@ -83,6 +83,10 @@ typedef struct Jpeg2000Tile {
> Jpeg2000QuantStyle qntsty[4];
> Jpeg2000POC poc;
> Jpeg2000TilePart tile_part[32];
> + uint8_t has_ppt; // whether this tile has a
> ppt marker
> + uint8_t *packed_headers; // contains packed headers.
> Used only along with PPT marker
> + int packed_headers_size; // size in bytes of the
> packed headers
> + GetByteContext packed_headers_stream; // byte context
> corresponding to packed headers
> uint16_t tp_idx; // Tile-part index
> int coord[2][2]; // border coordinates {{x0, x1},
> {y0, y1}}
> } Jpeg2000Tile;
> @@ -855,6 +859,39 @@ static int get_plt(Jpeg2000DecoderContext *s, int n)
> return 0;
> }
>
> +static int get_ppt(Jpeg2000DecoderContext *s, int n)
> +{
> + Jpeg2000Tile *tile;
> +
> + if (s->curtileno < 0)
> + return AVERROR_INVALIDDATA;
> +
> + tile = &s->tile[s->curtileno];
> + if (tile->tp_idx != 0) {
> + av_log(s->avctx, AV_LOG_ERROR,
> + "PPT marker can occur only on first tile part of a tile.\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + tile->has_ppt = 1; // this tile has a ppt marker
> +/* Zppt = */ bytestream2_get_byte(&s->g); // Zppt is skipped and not used
> + if (!tile->packed_headers) {
> + tile->packed_headers = av_malloc_array(n - 3, 1);
av_malloc() or av_realloc seems to make more sense here, the *1 isnt usefull
> + memcpy(tile->packed_headers, s->g.buffer, n - 3);
missing check for malloc failure
> + tile->packed_headers_size = n - 3;
> + } else {
> + tile->packed_headers = av_realloc_array(tile->packed_headers,
> + tile->packed_headers_size +
> n - 3,
> + 1);
> + memcpy(tile->packed_headers + tile->packed_headers_size,
> + s->g.buffer, n - 3);
> + tile->packed_headers_size += n - 3;
> + }
isnt packed_headers_size 0 before the initial allocation ?
if so the if and else can be simplified
> + bytestream2_skip(&s->g, n - 3);
> +
> + return 0;
> +}
> +
> static int init_tile(Jpeg2000DecoderContext *s, int tileno)
> {
> int compno;
> @@ -938,19 +975,23 @@ static int
> jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
> if (layno < rlevel->band[0].prec[precno].decoded_layers)
> return 0;
> rlevel->band[0].prec[precno].decoded_layers = layno + 1;
> -
> - if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
> - if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
> - s->g = tile->tile_part[++(*tp_index)].tpg;
> + // Select stream to read from
> + if (tile->has_ppt) {
> + s->g = tile->packed_headers_stream;
> + } else {
> + s->g = tile->tile_part[*tp_index].tpg;
> + if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
> + if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
> + s->g = tile->tile_part[++(*tp_index)].tpg;
> + }
> }
> + if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
> + bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
> }
>
> - if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
> - bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
> -
> if (!(ret = get_bits(s, 1))) {
> jpeg2000_flush(s);
> - return 0;
> + goto skip_data;
> } else if (ret < 0)
> return ret;
>
> @@ -1056,6 +1097,18 @@ static int
> jpeg2000_decode_packet(Jpeg2000DecoderContext *s, Jpeg2000Tile *tile,
> av_log(s->avctx, AV_LOG_ERROR, "EPH marker not found. instead
> %X\n", bytestream2_peek_be32(&s->g));
> }
>
> + // Save state of stream
> + if (tile->has_ppt) {
> + tile->packed_headers_stream = s->g;
> + s->g = tile->tile_part[*tp_index].tpg;
> + if (bytestream2_get_bytes_left(&s->g) == 0 && s->bit_index == 8) {
> + if (*tp_index < FF_ARRAY_ELEMS(tile->tile_part) - 1) {
> + s->g = tile->tile_part[++(*tp_index)].tpg;
> + }
> + }
> + if (bytestream2_peek_be32(&s->g) == JPEG2000_SOP_FIXED_BYTES)
> + bytestream2_skip(&s->g, JPEG2000_SOP_BYTE_LENGTH);
This looks like duplicated code, maybe this is cleaner if its factored into a
seperate function
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
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