On 11/14/2018 8:04 PM, Mark Thompson wrote: > On 14/11/18 22:39, James Almer wrote: >> On 11/14/2018 7:24 PM, Mark Thompson wrote: >>> On 11/11/18 02:24, James Almer wrote: >>>> Signed-off-by: James Almer <jamr...@gmail.com> >>>> --- >>>> See https://0x0.st/sljR.webm >>>> >>>> libavcodec/cbs_av1.c | 30 +++++++++--------------------- >>>> 1 file changed, 9 insertions(+), 21 deletions(-) >>>> >>>> diff --git a/libavcodec/cbs_av1.c b/libavcodec/cbs_av1.c >>>> index ff32a6fca5..215f9384e8 100644 >>>> --- a/libavcodec/cbs_av1.c >>>> +++ b/libavcodec/cbs_av1.c >>>> @@ -189,30 +189,26 @@ static int cbs_av1_read_su(CodedBitstreamContext >>>> *ctx, GetBitContext *gbc, >>>> int width, const char *name, >>>> const int *subscripts, int32_t *write_to) >>>> { >>>> - uint32_t magnitude; >>>> - int position, sign; >>>> + int position; >>>> int32_t value; >>>> >>>> if (ctx->trace_enable) >>>> position = get_bits_count(gbc); >>>> >>>> - if (get_bits_left(gbc) < width + 1) { >>>> + if (get_bits_left(gbc) < width) { >>>> av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid signed value at " >>>> "%s: bitstream ended.\n", name); >>>> return AVERROR_INVALIDDATA; >>>> } >>>> >>>> - magnitude = get_bits(gbc, width); >>>> - sign = get_bits1(gbc); >>>> - value = sign ? -(int32_t)magnitude : magnitude; >>>> + value = get_sbits(gbc, width); >>>> >>>> if (ctx->trace_enable) { >>>> char bits[33]; >>>> int i; >>>> for (i = 0; i < width; i++) >>>> - bits[i] = magnitude >> (width - i - 1) & 1 ? '1' : '0'; >>>> - bits[i] = sign ? '1' : '0'; >>>> - bits[i + 1] = 0; >>>> + bits[i] = value >> (width - i - 1) & 1 ? '1' : '0'; >>> >>> Not sure if we care, but right-shifting a negative value is >>> implementation-defined. >> >> Is casting value to unsigned enough, or should i use something like >> zero_extend()? > > I think using left-shift instead is safe: > > value & 1 << (...) ? '1' : '0'
Changed and both patches applied and backported. Thanks! _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
