avformat: add ff_reshuffle_raw_rgb()

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/internal.h

@@ -560,4 +560,12 @@ void ff_format_io_close(AVFormatContext *s, AVIOContext **pb);
  */
 int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds);
 
+/**
+ * Reshuffles the lines to use the user specified stride.
+ *
+ * @param ppkt input and output packet
+ * @return negative error code or 0 or 1, 1 indicates that ppkt needs to be freed
+ */
+int ff_reshuffle_raw_rgb(AVFormatContext *s, AVPacket **ppkt, AVCodecContext *enc, int expected_stride);
+
 #endif /* AVFORMAT_INTERNAL_H */

libavformat/rawutils.c

+/*
+ * Raw video utils
+ * Copyright (c) 2016 Michael Niedermayer
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avformat.h"
+#include "internal.h"
+
+int ff_reshuffle_raw_rgb(AVFormatContext *s, AVPacket **ppkt, AVCodecContext *enc, int expected_stride)
+{
+    int ret;
+    AVPacket *pkt = *ppkt;
+    int64_t bpc = enc->bits_per_coded_sample != 15 ? enc->bits_per_coded_sample : 16;
+    int min_stride = (enc->width * bpc + 7) >> 3;
+    int with_pal_size = min_stride * enc->height + 1024;
+    int size = bpc == 8 && pkt->size == with_pal_size ? min_stride * enc->height : pkt->size;
+    int stride = size / enc->height;
+    int padding = expected_stride - FFMIN(expected_stride, stride);
+    int y;
+    AVPacket *new_pkt;
+
+    if (pkt->size == expected_stride * enc->height)
+        return 0;
+    if (size != stride * enc->height)
+        return 0;
+
+    new_pkt = av_packet_alloc();
+    if (!new_pkt)
+        return AVERROR(ENOMEM);
+
+    ret = av_new_packet(new_pkt, expected_stride * enc->height);
+    if (ret < 0)
+        goto fail;
+
+    ret = av_packet_copy_props(new_pkt, pkt);
+    if (ret < 0)
+        goto fail;
+
+    for (y = 0; y<enc->height; y++) {
+        memcpy(new_pkt->data + y*expected_stride, pkt->data + y*stride, FFMIN(expected_stride, stride));
+        memset(new_pkt->data + y*expected_stride + expected_stride - padding, 0, padding);
+    }
+
+    *ppkt = new_pkt;
+    return 1;
+fail:
+    av_packet_free(&new_pkt);
+
+    return ret;
+}