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CrystalHD: Refine heuristic logic.

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This commit is contained in:
Philip Langdale 2011-03-20 16:29:04 -07:00
parent 4ab57cffba
commit f968ef922d
1 changed files with 27 additions and 28 deletions
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55
libavcodec/crystalhd.c
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@ -512,8 +512,7 @@ static inline CopyRet copy_frame(AVCodecContext *avctx,
{
BC_STATUS ret;
BC_DTS_STATUS decoder_status;
uint8_t confirmed_interlaced;
uint8_t ignore_interlaced;
uint8_t trust_interlaced;
uint8_t interlaced;
CHDContext *priv = avctx->priv_data;
@ -561,50 +560,50 @@ static inline CopyRet copy_frame(AVCodecContext *avctx,
}
/*
* If we're expecting a second field, or we know that the next
* picture has the same number as the current picture, then we're
* definitely interlaced.
* For most content, we can trust the interlaced flag returned
* by the hardware, but sometimes we can't. These are the
* conditions under which we can trust the flag:
*
* Note that this test can return false negatives if the hardware
* hasn't decoded the next picture or if there is a corruption in
* the stream. (In either case a 0 will be returned for the next
* picture number)
* 1) It's not h.264 content
* 2) The UNKNOWN_SRC flag is not set
* 3) We know we're expecting a second field
* 4) The hardware reports this picture and the next picture
* have the same picture number.
*
* Note that there can still be interlaced content that will
* fail this check, if the hardware hasn't decoded the next
* picture or if there is a corruption in the stream. (In either
* case a 0 will be returned for the next picture number)
*/
confirmed_interlaced = ((decoder_status.picNumFlags & ~0x40000000) ==
output->PicInfo.picture_number) ||
priv->need_second_field;
trust_interlaced = avctx->codec->id != CODEC_ID_H264 ||
!(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) ||
priv->need_second_field ||
(decoder_status.picNumFlags & ~0x40000000) ==
output->PicInfo.picture_number;
/*
* If we got a false negative for confirmed_interlaced on the first field,
* If we got a false negative for trust_interlaced on the first field,
* we will realise our mistake here when we see that the picture number is that
* of the previous picture. We cannot recover the frame and should discard the
* second field to keep the correct number of output frames.
*/
if (output->PicInfo.picture_number == priv->last_picture && !priv->need_second_field) {
av_log(avctx, AV_LOG_WARNING,
"Incorrectly guessed progressie frame. Discarding second field\n");
"Incorrectly guessed progressive frame. Discarding second field\n");
/* Returning without providing a picture. */
return RET_OK;
}
/*
* Testing has, so far, shown that we can't trust the interlaced flag for
* H.264 content when VDEC_FLAG_UNKNOWN_SRC is set.
*/
ignore_interlaced = avctx->codec->id == CODEC_ID_H264 &&
(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) &&
(pic_type == 0 || pic_type == PICT_FRAME ||
!confirmed_interlaced);
interlaced = (output->PicInfo.flags & VDEC_FLAG_INTERLACED_SRC) &&
(!ignore_interlaced || confirmed_interlaced);
interlaced = (output->PicInfo.flags & VDEC_FLAG_INTERLACED_SRC) &&
trust_interlaced;
if (ignore_interlaced && (decoder_status.picNumFlags & ~0x40000000) == 0) {
av_log(avctx, AV_LOG_WARNING,
if (!trust_interlaced && (decoder_status.picNumFlags & ~0x40000000) == 0) {
av_log(avctx, AV_LOG_VERBOSE,
"Next picture number unknown. Assuming progressive frame.\n");
}
av_log(avctx, AV_LOG_VERBOSE, "Interlaced state: %d | ignore_interlaced %d\n",
interlaced, ignore_interlaced);
av_log(avctx, AV_LOG_VERBOSE, "Interlaced state: %d | trust_interlaced %d\n",
interlaced, trust_interlaced);
if (priv->pic.data[0] && !priv->need_second_field)
avctx->release_buffer(avctx, &priv->pic);