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/*
* This file is part of mpv.
*
* mpv 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.
*
* mpv 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 mpv. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libavutil/common.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include "common/common.h"
#include "options/m_option.h"
#include "options/path.h"
#include "stream.h"
struct priv {
int64_t slice_start;
int64_t slice_max_end; // 0 for no limit
struct stream *inner;
};
static int fill_buffer(struct stream *s, void *buffer, int len)
{
struct priv *p = s->priv;
if (p->slice_max_end) {
// We don't simply use (s->pos >= size) to avoid early return
// if the file is still being appended to.
if (s->pos + p->slice_start >= p->slice_max_end)
return -1;
// Avoid rading beyond p->slice_max_end
len = MPMIN(len, p->slice_max_end - s->pos);
}
return stream_read_partial(p->inner, buffer, len);
}
static int seek(struct stream *s, int64_t newpos)
{
struct priv *p = s->priv;
return stream_seek(p->inner, newpos + p->slice_start);
}
static int64_t get_size(struct stream *s)
{
struct priv *p = s->priv;
int64_t size = stream_get_size(p->inner);
if (size <= 0)
return size;
if (size <= p->slice_start)
return 0;
if (p->slice_max_end)
size = MPMIN(size, p->slice_max_end);
return size - p->slice_start;
}
static void s_close(struct stream *s)
{
struct priv *p = s->priv;
free_stream(p->inner);
}
static int parse_slice_range(stream_t *stream)
{
struct priv *p = stream->priv;
struct bstr b_url = bstr0(stream->url);
struct bstr proto_with_range, inner_url;
bool has_at = bstr_split_tok(b_url, "@", &proto_with_range, &inner_url);
if (!has_at) {
MP_ERR(stream, "Expected slice://start[-end]@URL: '%s'\n", stream->url);
return STREAM_ERROR;
}
if (!inner_url.len) {
MP_ERR(stream, "URL expected to follow 'slice://start[-end]@': '%s'.\n", stream->url);
return STREAM_ERROR;
}
stream->path = bstrto0(stream, inner_url);
mp_split_proto(proto_with_range, &proto_with_range);
struct bstr range = proto_with_range;
struct bstr start, end;
bool has_end = bstr_split_tok(range, "-", &start, &end);
if (!start.len) {
MP_ERR(stream, "The byte range must have a start, and it can't be negative: '%s'\n", stream->url);
return STREAM_ERROR;
}
if (has_end && !end.len) {
MP_ERR(stream, "The byte range end can be omitted, but it can't be empty: '%s'\n", stream->url);
return STREAM_ERROR;
}
const struct m_option opt = {
.type = &m_option_type_byte_size,
};
if (m_option_parse(stream->log, &opt, bstr0("slice_start"), start, &p->slice_start) < 0)
return STREAM_ERROR;
bool max_end_is_offset = bstr_startswith0(end, "+");
if (has_end) {
if (m_option_parse(stream->log, &opt, bstr0("slice_max_end"), end, &p->slice_max_end) < 0)
return STREAM_ERROR;
}
if (max_end_is_offset)
p->slice_max_end += p->slice_start;
if (p->slice_max_end && p->slice_max_end < p->slice_start) {
MP_ERR(stream, "The byte range end (%"PRId64") can't be smaller than the start (%"PRId64"): '%s'\n",
p->slice_max_end,
p->slice_start,
stream->url);
return STREAM_ERROR;
}
return STREAM_OK;
}
static int open2(struct stream *stream, struct stream_open_args *args)
{
struct priv *p = talloc_zero(stream, struct priv);
stream->priv = p;
stream->fill_buffer = fill_buffer;
stream->seek = seek;
stream->get_size = get_size;
stream->close = s_close;
int parse_ret = parse_slice_range(stream);
if (parse_ret != STREAM_OK) {
return parse_ret;
}
args->url = stream->path;
int inner_ret = stream_create_with_args(args, &p->inner);
if (inner_ret != STREAM_OK) {
return inner_ret;
}
if (!p->inner->seekable) {
MP_FATAL(stream, "Non-seekable stream '%s' can't be used with 'slice://'\n", p->inner->url);
free_stream(p->inner);
return STREAM_ERROR;
}
stream->seekable = 1;
stream->stream_origin = p->inner->stream_origin;
if (p->slice_start)
seek(stream, 0);
return STREAM_OK;
}
const stream_info_t stream_info_slice = {
.name = "slice",
.open2 = open2,
.protocols = (const char*const[]){ "slice", NULL },
.can_write = false,
};
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