62     ThreadFrame last_picture;  member
1030     if ((sequence_number == 0 || !s->last_picture.f->data[0]) &&  in decode_fctl_chunk()
1062     uint8_t *pd_last = s->last_picture.f->data[0];  in handle_p_frame_png()
1067     ff_thread_await_progress(&s->last_picture, INT_MAX, 0);  in handle_p_frame_png()
1072         pd_last += s->last_picture.f->linesize[0];  in handle_p_frame_png()
1085     const uint8_t *src        = s->last_picture.f->data[0];  in handle_p_frame_apng()
1086     ptrdiff_t      src_stride = s->last_picture.f->linesize[0];  in handle_p_frame_apng()
1099     ff_thread_await_progress(&s->last_picture, INT_MAX, 0);  in handle_p_frame_apng()
1438     if (s->last_picture.f->data[0]) {  in decode_frame_common()
1440             && s->last_picture.f->width == p->width  in decode_frame_common()
1441             && s->last_picture.f->height== p->height  in decode_frame_common()
1442             && s->last_picture.f->format== p->format  in decode_frame_common()
1575         ff_thread_release_ext_buffer(avctx, &s->last_picture);  in decode_frame_png()
1576         FFSWAP(ThreadFrame, s->picture, s->last_picture);  in decode_frame_png()
1630             ff_thread_release_ext_buffer(avctx, &s->last_picture);  in decode_frame_apng()
1631             FFSWAP(ThreadFrame, s->picture, s->last_picture);  in decode_frame_apng()
1669                 &psrc->last_picture : &psrc->picture;  in update_thread_context()
1671     ff_thread_release_ext_buffer(dst, &pdst->last_picture);  in update_thread_context()
1673         ret = ff_thread_ref_frame(&pdst->last_picture, src_frame);  in update_thread_context()
1689     s->last_picture.f = av_frame_alloc();  in png_dec_init()
1691     if (!s->last_picture.f || !s->picture.f)  in png_dec_init()
1703     ff_thread_release_ext_buffer(avctx, &s->last_picture);  in png_dec_end()
1704     av_frame_free(&s->last_picture.f);  in png_dec_end()