avformat/segafilmenc: use ff_format_shift_data for shifting

Signed-off-by: Marton Balint <cus@passwd.hu>
This commit is contained in:
Marton Balint 2021-12-11 19:28:50 +01:00
parent 10a0a8ca83
commit 26d6c81dc6
1 changed files with 4 additions and 45 deletions

View File

@ -170,54 +170,13 @@ static int film_init(AVFormatContext *format_context)
static int write_header(AVFormatContext *format_context, uint8_t *header,
unsigned header_size)
{
int ret = 0;
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(header_size);
if (!buf)
return AVERROR(ENOMEM);
read_buf[0] = buf;
read_buf[1] = header;
read_size[1] = header_size;
/* Write the header at the beginning of the file, shifting all content as necessary;
* based on the approach used by MOV faststart. */
avio_flush(format_context->pb);
ret = format_context->io_open(format_context, &read_pb, format_context->url, AVIO_FLAG_READ, NULL);
if (ret < 0) {
av_log(format_context, AV_LOG_ERROR, "Unable to re-open %s output file to "
"write the header\n", format_context->url);
av_free(buf);
int ret = ff_format_shift_data(format_context, 0, header_size);
if (ret < 0)
return ret;
}
/* Mark the end of the shift to up to the last data we are going to write,
* and get ready for writing */
pos_end = avio_tell(format_context->pb) + header_size;
pos = avio_seek(format_context->pb, 0, SEEK_SET);
avio_seek(format_context->pb, 0, SEEK_SET);
avio_write(format_context->pb, header, header_size);
/* start reading at where the new header will be placed */
avio_seek(read_pb, 0, SEEK_SET);
/* shift data by chunk of at most header_size */
do {
int n;
read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id],
header_size);
read_buf_id ^= 1;
n = read_size[read_buf_id];
if (n <= 0)
break;
avio_write(format_context->pb, read_buf[read_buf_id], n);
pos += n;
} while (pos < pos_end);
ff_format_io_close(format_context, &read_pb);
av_free(buf);
return 0;
}