avformat/mux_utils: Move ff_format_shift_data to new file for mux utils

It is only used by muxers. Given that it is not part of
the core muxing code and given that mux.c is already big enough,
it is moved to a new file for utility functions for muxing.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 0 insertions, 56 deletions

diff --git a/libavformat/utils.c b/libavformat/utils.c
index f31dda9b44..b53e2aff0c 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1832,59 +1832,3 @@ void ff_format_set_url(AVFormatContext *s, char *url)
     av_freep(&s->url);
     s->url = url;
 }
-
-int ff_format_shift_data(AVFormatContext *s, int64_t read_start, int shift_size)
-{
-    int ret;
-    int64_t pos, pos_end;
-    uint8_t *buf, *read_buf[2];
-    int read_buf_id = 0;
-    int read_size[2];
-    AVIOContext *read_pb;
-
-    buf = av_malloc_array(shift_size, 2);
-    if (!buf)
-        return AVERROR(ENOMEM);
-    read_buf[0] = buf;
-    read_buf[1] = buf + shift_size;
-
-    /* Shift the data: the AVIO context of the output can only be used for
-     * writing, so we re-open the same output, but for reading. It also avoids
-     * a read/seek/write/seek back and forth. */
-    avio_flush(s->pb);
-    ret = s->io_open(s, &read_pb, s->url, AVIO_FLAG_READ, NULL);
-    if (ret < 0) {
-        av_log(s, AV_LOG_ERROR, "Unable to re-open %s output file for shifting data\n", s->url);
-        goto end;
-    }
-
-    /* mark the end of the shift to up to the last data we wrote, and get ready
-     * for writing */
-    pos_end = avio_tell(s->pb);
-    avio_seek(s->pb, read_start + shift_size, SEEK_SET);
-
-    avio_seek(read_pb, read_start, SEEK_SET);
-    pos = avio_tell(read_pb);
-
-#define READ_BLOCK do {                                                             \
-    read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], shift_size);  \
-    read_buf_id ^= 1;                                                               \
-} while (0)
-
-    /* shift data by chunk of at most shift_size */
-    READ_BLOCK;
-    do {
-        int n;
-        READ_BLOCK;
-        n = read_size[read_buf_id];
-        if (n <= 0)
-            break;
-        avio_write(s->pb, read_buf[read_buf_id], n);
-        pos += n;
-    } while (pos < pos_end);
-    ret = ff_format_io_close(s, &read_pb);
-
-end:
-    av_free(buf);
-    return ret;
-}