[FFmpeg-devel] [PATCH 2/3] ffv1dec: move header parsing into a separate function
Lynne
dev at lynne.ee
Sun Jan 5 10:59:36 EET 2025
---
libavcodec/ffv1dec.c | 64 +++++++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 24 deletions(-)
diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index aa988571bc..68a233932d 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -548,11 +548,10 @@ static enum AVPixelFormat get_pixel_format(FFV1Context *f)
return ff_get_format(f->avctx, pix_fmts);
}
-static int read_header(FFV1Context *f)
+static int read_header(FFV1Context *f, RangeCoder *c)
{
uint8_t state[CONTEXT_SIZE];
int context_count = -1; //-1 to avoid warning
- RangeCoder *const c = &f->slices[0].c;
memset(state, 128, sizeof(state));
@@ -898,31 +897,20 @@ static int find_next_slice(AVCodecContext *avctx,
return 0;
}
-static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
- int *got_frame, AVPacket *avpkt)
+static int decode_header(AVCodecContext *avctx, RangeCoder *c,
+ uint8_t *buf, size_t buf_size)
{
- uint8_t *buf = avpkt->data;
- int buf_size = avpkt->size;
- FFV1Context *f = avctx->priv_data;
- RangeCoder *const c = &f->slices[0].c;
- int ret, key_frame;
- uint8_t keystate = 128;
- uint8_t *buf_end;
- AVFrame *p;
-
- ff_progress_frame_unref(&f->last_picture);
- FFSWAP(ProgressFrame, f->picture, f->last_picture);
-
+ int ret;
+ FFV1Context *f = avctx->priv_data;
- f->avctx = avctx;
- f->frame_damaged = 0;
+ uint8_t keystate = 128;
ff_init_range_decoder(c, buf, buf_size);
ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);
if (get_rac(c, &keystate)) {
- key_frame = AV_FRAME_FLAG_KEY;
+ f->key_frame = AV_FRAME_FLAG_KEY;
f->key_frame_ok = 0;
- if ((ret = read_header(f)) < 0)
+ if ((ret = read_header(f, c)) < 0)
return ret;
f->key_frame_ok = 1;
} else {
@@ -931,7 +919,7 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
"Cannot decode non-keyframe without valid keyframe\n");
return AVERROR_INVALIDDATA;
}
- key_frame = 0;
+ f->key_frame = 0;
}
if (f->ac != AC_GOLOMB_RICE) {
@@ -950,6 +938,33 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
return AVERROR_INVALIDDATA;
}
+ return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
+ int *got_frame, AVPacket *avpkt)
+{
+ uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
+ FFV1Context *f = avctx->priv_data;
+ int ret;
+ uint8_t *buf_end;
+ AVFrame *p;
+
+ /* This is copied onto the first slice's range coder context */
+ RangeCoder c;
+
+ ff_progress_frame_unref(&f->last_picture);
+ FFSWAP(ProgressFrame, f->picture, f->last_picture);
+
+
+ f->avctx = avctx;
+ f->frame_damaged = 0;
+
+ ret = decode_header(avctx, &c, avpkt->data, avpkt->size);
+ if (ret < 0)
+ return ret;
+
ret = ff_progress_frame_get_buffer(avctx, &f->picture,
AV_GET_BUFFER_FLAG_REF);
if (ret < 0)
@@ -958,7 +973,7 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
p = f->picture.f;
p->pict_type = AV_PICTURE_TYPE_I; //FIXME I vs. P
- p->flags = (p->flags & ~AV_FRAME_FLAG_KEY) | key_frame;
+ p->flags = (p->flags & ~AV_FRAME_FLAG_KEY) | f->key_frame;
if (f->version < 3 && avctx->field_order > AV_FIELD_PROGRESSIVE) {
/* we have interlaced material flagged in container */
@@ -1010,9 +1025,10 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *rframe,
if (i) {
ff_init_range_decoder(&sc->c, pos, len);
ff_build_rac_states(&sc->c, 0.05 * (1LL << 32), 256 - 8);
- } else
+ } else {
+ sc->c = c;
sc->c.bytestream_end = pos + len;
-
+ }
}
avctx->execute(avctx,
--
2.45.2
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