h264: revert 1189af42.

The patch introduces race conditions.

libavcodec/h264_slice.c

@@ -383,9 +383,6 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
     h->picture_structure    = h1->picture_structure;
     h->mb_aff_frame         = h1->mb_aff_frame;
     h->droppable            = h1->droppable;
-    h->backup_width         = h1->backup_width;
-    h->backup_height        = h1->backup_height;
-    h->backup_pix_fmt       = h1->backup_pix_fmt;
 
     for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {
         ff_h264_unref_picture(h, &h->DPB[i]);

libavcodec/h264dec.c

@@ -307,9 +307,6 @@ static int h264_init_context(AVCodecContext *avctx, H264Context *h)
     int i;
 
     h->avctx                 = avctx;
-    h->backup_width          = -1;
-    h->backup_height         = -1;
-    h->backup_pix_fmt        = AV_PIX_FMT_NONE;
     h->cur_chroma_format_idc = -1;
 
     h->picture_structure     = PICT_FRAME;
@@ -861,14 +858,6 @@ static int output_frame(H264Context *h, AVFrame *dst, H264Picture *srcp)
 
     av_dict_set(&dst->metadata, "stereo_mode", ff_h264_sei_stereo_mode(&h->sei.frame_packing), 0);
 
-    h->backup_width   = h->avctx->width;
-    h->backup_height  = h->avctx->height;
-    h->backup_pix_fmt = h->avctx->pix_fmt;
-
-    h->avctx->width   = dst->width;
-    h->avctx->height  = dst->height;
-    h->avctx->pix_fmt = dst->format;
-
     if (srcp->sei_recovery_frame_cnt == 0)
         dst->key_frame = 1;
     if (!srcp->crop)
@@ -1003,19 +992,6 @@ static int h264_decode_frame(AVCodecContext *avctx, void *data,
     h->setup_finished = 0;
     h->nb_slice_ctx_queued = 0;
 
-    if (h->backup_width != -1) {
-        avctx->width    = h->backup_width;
-        h->backup_width = -1;
-    }
-    if (h->backup_height != -1) {
-        avctx->height    = h->backup_height;
-        h->backup_height = -1;
-    }
-    if (h->backup_pix_fmt != AV_PIX_FMT_NONE) {
-        avctx->pix_fmt    = h->backup_pix_fmt;
-        h->backup_pix_fmt = AV_PIX_FMT_NONE;
-    }
-
     ff_h264_unref_picture(h, &h->last_pic_for_ec);
 
     /* end of stream, output what is still in the buffers */

libavcodec/h264dec.h

@@ -363,14 +363,6 @@ typedef struct H264Context {
     int width, height;
     int chroma_x_shift, chroma_y_shift;
 
-    /**
-     * Backup frame properties: needed, because they can be different
-     * between returned frame and last decoded frame.
-     **/
-    int backup_width;
-    int backup_height;
-    enum AVPixelFormat backup_pix_fmt;
-
     int droppable;
     int coded_picture_number;