On Sat, Feb 20, 2021 at 11:11 PM Andreas Rheinhardt <
andreas.rheinha...@gmail.com> wrote:
> Paul B Mahol:
> > Signed-off-by: Paul B Mahol
> > ---
> > libavcodec/exr.c | 212 +++
> > 1 file changed, 65 insertions(+), 147 deletions(-)
> >
> > diff --git a/libavcodec/exr.c b/libavcodec/exr.c
> > index cacdff5774..625ee4680c 100644
> > --- a/libavcodec/exr.c
> > +++ b/libavcodec/exr.c
> > @@ -91,6 +91,12 @@ enum ExrTileLevelRound {
> > EXR_TILE_ROUND_UNKNOWN,
> > };
> >
> > +typedef struct HuffEntry {
> > +uint8_t len;
> > +uint16_t sym;
> > +uint16_t code;
>
> The old code allowed codes with a length of <= 58. This is more than our
> VLC-API allows and even more than fits into a 16-bit code. You seem to
> believe that all codes have a length <= 16 just because HUF_ENCBITS is
> 16. But this is wrong: It just means that there are at most 1<<16
> ordinary symbols and one special symbol for runs. It also means that we
> can't even distinguish all possible symbols because VLC_TYPE is 16 bits.
>
Fixed to use 32bits code, also added messages to ask for sample if more is
needed.
> > +} HuffEntry;
> > +
> > typedef struct EXRChannel {
> > int xsub, ysub;
> > enum ExrPixelType pixel_type;
> > @@ -116,6 +122,11 @@ typedef struct EXRThreadData {
> > int ysize, xsize;
> >
> > int channel_line_size;
> > +
> > +uint16_t run_sym;
> > +HuffEntry *he;
> > +uint64_t *freq;
> > +VLC vlc;
> > } EXRThreadData;
> >
> > typedef struct EXRContext {
> > @@ -319,11 +330,8 @@ static void apply_lut(const uint16_t *lut, uint16_t
> *dst, int dsize)
> > }
> >
> > #define HUF_ENCBITS 16 // literal (value) bit length
> > -#define HUF_DECBITS 14 // decoding bit size (>= 8)
> >
> > #define HUF_ENCSIZE ((1 << HUF_ENCBITS) + 1) // encoding table size
> > -#define HUF_DECSIZE (1 << HUF_DECBITS)// decoding table size
> > -#define HUF_DECMASK (HUF_DECSIZE - 1)
> >
> > typedef struct HufDec {
> > int len;
> > @@ -336,7 +344,7 @@ static void huf_canonical_code_table(uint64_t *hcode)
> > uint64_t c, n[59] = { 0 };
> > int i;
> >
> > -for (i = 0; i < HUF_ENCSIZE; ++i)
> > +for (i = 0; i < HUF_ENCSIZE; i++)
>
> Spurious change.
>
> > n[hcode[i]] += 1;
> >
> > c = 0;
> > @@ -399,149 +407,63 @@ static int huf_unpack_enc_table(GetByteContext
> *gb,
> > return 0;
> > }
> >
> > -static int huf_build_dec_table(const uint64_t *hcode, int im,
> > - int iM, HufDec *hdecod)
> > +static int huf_build_dec_table(EXRThreadData *td, int im, int iM)
> > {
> > -for (; im <= iM; im++) {
> > -uint64_t c = hcode[im] >> 6;
> > -int i, l = hcode[im] & 63;
> > -
> > -if (c >> l)
> > -return AVERROR_INVALIDDATA;
> > -
> > -if (l > HUF_DECBITS) {
> > -HufDec *pl = hdecod + (c >> (l - HUF_DECBITS));
> > -if (pl->len)
> > -return AVERROR_INVALIDDATA;
> > -
> > -pl->lit++;
> > -
> > -pl->p = av_realloc(pl->p, pl->lit * sizeof(int));
> > -if (!pl->p)
> > -return AVERROR(ENOMEM);
> > -
> > -pl->p[pl->lit - 1] = im;
> > -} else if (l) {
> > -HufDec *pl = hdecod + (c << (HUF_DECBITS - l));
> > -
> > -for (i = 1 << (HUF_DECBITS - l); i > 0; i--, pl++) {
> > -if (pl->len || pl->p)
> > -return AVERROR_INVALIDDATA;
> > -pl->len = l;
> > -pl->lit = im;
> > -}
> > -}
> > +int j = 0;
> > +
> > +for (int i = im; i < iM; i++) {
> > +td->he[j].sym = i;
> > +td->he[j].len = td->freq[i] & 63;
> > +td->he[j].code = td->freq[i] >> 6;> +if (td->he[j].len
> > 0)
> > +j++;
> > +else
> > +td->run_sym = i;
> > }
> >
> > -return 0;
> > -}
> > -
> > -#define get_char(c, lc, gb)
>\
> > -{
>\
> > -c = (c << 8) | bytestream2_get_byte(gb);
> \
> > -lc += 8;
> \
> > -}
> > +td->he[j].sym = td->run_sym;
> > +td->he[j].len = td->freq[iM] & 63;
> > +td->he[j].code = td->freq[iM] >> 6;
> > +j++;
> >
> > -#define get_code(po, rlc, c, lc, gb, out, oe, outb)
>\
> > -{
>\
> > -if (po == rlc) {
> \
> > -if (lc < 8)
>\
> > -get_char(c, lc, gb);
> \
> > -lc -= 8;
> \
> > -
> \
> > -cs = c >> lc;
>\
> > -
> \
> > -if (out + cs > oe || out == outb)
>\
> > -return AVERROR_INVALIDDATA;
>\
> > -
> \
> > -s = out[-1];
> \
> > -
> \
> > -while (cs-- > 0)
> \
> > -*out++ = s;
>\
> > -} else if (out < oe) {
> \
> > -*out++ = po;
> \
> > -} else {
> \
