[FFmpeg-devel] [PATCH 2/3] libavformat/dashdec: Fix for ticket 6658 (Dash demuxer segfault)
刘歧
lq at chinaffmpeg.org
Wed Jan 17 05:39:03 EET 2018
> On 17 Jan 2018, at 11:00, Colin NG <colin_ng at hotmail.com> wrote:
>
> - Add function 'resolve_content_path' to propagate the baseURL from upper level nodes.
> * if no baseURL is available, the path of mpd file will be set as the baseURL.
> - Remove checking for newly established connection.
> - Establish the communication protocol in each connection rather than applying one protocol to all connection.
> ---
> libavformat/dashdec.c | 128 +++++++++++++++++++++++++++++++++++++++++++++-----
> 1 file changed, 115 insertions(+), 13 deletions(-)
>
> diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
> index 67a92d6..1d520d4 100644
> --- a/libavformat/dashdec.c
> +++ b/libavformat/dashdec.c
> @@ -149,6 +149,11 @@ typedef struct DASHContext {
> AVDictionary *avio_opts;
> } DASHContext;
>
> +static int ishttp(char *url) {
> + const char *proto_name = avio_find_protocol_name(url);
> + return av_strstart(proto_name, "http", NULL);
> +}
> +
> static uint64_t get_current_time_in_sec(void)
> {
> return av_gettime() / 1000000;
> @@ -420,7 +425,8 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
> else if (strcmp(proto_name, "file") || !strncmp(url, "file,", 5))
> return AVERROR_INVALIDDATA;
>
> - ret = s->io_open(s, pb, url, AVIO_FLAG_READ, &tmp);
> + av_freep(pb);
> + ret = avio_open2(pb, url, AVIO_FLAG_READ, c->interrupt_callback, &tmp);
> if (ret >= 0) {
> // update cookies on http response with setcookies.
> char *new_cookies = NULL;
> @@ -564,6 +570,7 @@ static struct fragment * get_Fragment(char *range)
> seg->url_offset = strtoll(str_offset, NULL, 10);
> seg->size = strtoll(str_end_offset, NULL, 10) - seg->url_offset;
> }
> +
> return seg;
> }
>
> @@ -591,6 +598,7 @@ static int parse_manifest_segmenturlnode(AVFormatContext *s, struct representati
> rep_id_val,
> rep_bandwidth_val,
> initialization_val);
> +
> if (!rep->init_section->url) {
> av_free(rep->init_section);
> xmlFree(initialization_val);
> @@ -665,6 +673,105 @@ static int parse_manifest_segmenttimeline(AVFormatContext *s, struct representat
> return 0;
> }
>
> +static int resolve_content_path(AVFormatContext *s, const char *url, xmlNodePtr *baseurl_nodes, int n_baseurl_nodes) {
> +
> + char *tmp_str = NULL;
> + char *path = NULL;
> + char *mpdName = NULL;
> + xmlNodePtr node = NULL;
> + char *baseurl = NULL;
> + char *root_url = NULL;
> + char *text = NULL;
> +
> + int isRootHttp = 0;
> + char token ='/';
> + int start = 0;
> + int rootId = 0;
> + int updated = 0;
> + int size = 0;
> + int i;
> + int max_url_size = strlen(url);
> +
> + for (i = n_baseurl_nodes-1; i >= 0 ; i--) {
> + text = xmlNodeGetContent(baseurl_nodes[i]);
> + if (!text)
> + continue;
> + max_url_size += strlen(text);
> + if (ishttp(text)) {
> + xmlFree(text);
> + break;
> + }
> + xmlFree(text);
> + }
> +
> + text = av_mallocz(max_url_size);
> + if (!text) {
> + updated = AVERROR(ENOMEM);
> + goto end;
> + }
> + av_strlcpy(text, url, strlen(url)+1);
> + while (mpdName = av_strtok(text, "/", &text)) {
> + size = strlen(mpdName);
> + }
> +
> + path = av_mallocz(max_url_size);
> + tmp_str = av_mallocz(max_url_size);
> + if (!tmp_str || !path) {
> + updated = AVERROR(ENOMEM);
> + goto end;
> + }
> +
> + av_strlcpy (path, url, strlen(url) - size + 1);
> + for (rootId = n_baseurl_nodes - 1; rootId > 0; rootId --) {
> + if (!(node = baseurl_nodes[rootId])) {
> + continue;
> + }
> + if (ishttp(xmlNodeGetContent(node))) {
> + break;
> + }
> + }
> +
> + node = baseurl_nodes[rootId];
> + baseurl = xmlNodeGetContent(node);
> + root_url = (av_strcasecmp(baseurl, "")) ? baseurl : path;
> + if (node) {
> + xmlNodeSetContent(node, root_url);
> + updated = 1;
> + }
> +
> + size = strlen(root_url);
> + isRootHttp = ishttp(root_url);
> +
> + if (root_url[size - 1] != token) {
> + av_strlcat(root_url, "/", size + 2);
> + size += 2;
> + }
> +
> + for (i = 0; i < n_baseurl_nodes; ++i) {
> + if (i == rootId) {
> + continue;
> + }
> + text = xmlNodeGetContent(baseurl_nodes[i]);
> + if (text) {
> + memset(tmp_str, 0, strlen(tmp_str));
> + if (!ishttp(text) && isRootHttp) {
> + av_strlcpy(tmp_str, root_url, size + 1);
> + }
> + start = (text[0] == token);
> + av_strlcat(tmp_str, text + start, max_url_size);
> + xmlNodeSetContent(baseurl_nodes[i], tmp_str);
> + updated = 1;
> + xmlFree(text);
> + }
> + }
> +
> +end:
> + av_free(path);
> + av_free(tmp_str);
> + return updated;
> +
> +}
> +
> static int parse_manifest_representation(AVFormatContext *s, const char *url,
> xmlNodePtr node,
> xmlNodePtr adaptionset_node,
> @@ -727,6 +834,10 @@ static int parse_manifest_representation(AVFormatContext *s, const char *url,
> baseurl_nodes[2] = adaptionset_baseurl_node;
> baseurl_nodes[3] = representation_baseurl_node;
>
> + ret = resolve_content_path(s, url, baseurl_nodes, 4);
> + if (ret == AVERROR(ENOMEM) || (ret == 0)) {
> + goto end;
> + }
> if (representation_segmenttemplate_node || fragment_template_node || period_segmenttemplate_node) {
> fragment_timeline_node = NULL;
> fragment_templates_tab[0] = representation_segmenttemplate_node;
> @@ -1038,6 +1149,9 @@ static int parse_manifest(AVFormatContext *s, const char *url, AVIOContext *in)
> }
>
> mpd_baseurl_node = find_child_node_by_name(node, "BaseURL");
> + if (!mpd_baseurl_node) {
> + mpd_baseurl_node = xmlNewNode(NULL, "BaseURL");
> + }
>
> // at now we can handle only one period, with the longest duration
> node = xmlFirstElementChild(node);
> @@ -1405,18 +1519,6 @@ static int open_input(DASHContext *c, struct representation *pls, struct fragmen
> goto cleanup;
> }
>
> - /* Seek to the requested position. If this was a HTTP request, the offset
> - * should already be where want it to, but this allows e.g. local testing
> - * without a HTTP server. */
> - if (!ret && seg->url_offset) {
> - int64_t seekret = avio_seek(pls->input, seg->url_offset, SEEK_SET);
> - if (seekret < 0) {
> - av_log(pls->parent, AV_LOG_ERROR, "Unable to seek to offset %"PRId64" of DASH fragment '%s'\n", seg->url_offset, seg->url);
> - ret = (int) seekret;
> - ff_format_io_close(pls->parent, &pls->input);
> - }
> - }
> -
> cleanup:
> av_dict_free(&opts);
> pls->cur_seg_offset = 0;
> --
> 2.7.4
>
Patchset LGTM, but there have some compiling warning:
liuqideMacBook-Pro:dash liuqi$ make
CC libavformat/dashdec.o
src/libavformat/dashdec.c:1530:9: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
if (!url) {
^~~~
src/libavformat/dashdec.c:1554:12: note: uninitialized use occurs here
return ret;
^~~
src/libavformat/dashdec.c:1530:5: note: remove the 'if' if its condition is always false
if (!url) {
^~~~~~~~~~~
src/libavformat/dashdec.c:1528:12: note: initialize the variable 'ret' to silence this warning
int ret;
^
= 0
1 warning generated.
AR libavformat/libavformat.a
LD ffmpeg_g
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