[FFmpeg-devel] [PATCH v2 1/3] avformat/argo_asf: cleanup and NULL-terminate name field in header

["zhilizhao(赵志立)"]

> On Oct 12, 2021, at 7:02 PM, Zane van Iperen <zane at zanevaniperen.com> wrote:
> 
> Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
> ---
> libavformat/argo_asf.c | 8 ++++----
> libavformat/argo_asf.h | 3 ++-
> 2 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/libavformat/argo_asf.c b/libavformat/argo_asf.c
> index 7e759c7c0c..acf30839b9 100644
> --- a/libavformat/argo_asf.c
> +++ b/libavformat/argo_asf.c
> @@ -52,8 +52,8 @@ void ff_argo_asf_parse_file_header(ArgoASFFileHeader *hdr, const uint8_t *buf)
>     hdr->version_minor  = AV_RL16(buf + 6);
>     hdr->num_chunks     = AV_RL32(buf + 8);
>     hdr->chunk_offset   = AV_RL32(buf + 12);
> -    for (int i = 0; i < FF_ARRAY_ELEMS(hdr->name); i++)
> -        hdr->name[i]    = AV_RL8(buf + 16 + i);
> +    memcpy(hdr->name, buf + 16, ASF_NAME_SIZE);
> +    hdr->name[ASF_NAME_SIZE] = '\0';
> }
> 
> int ff_argo_asf_validate_file_header(AVFormatContext *s, const ArgoASFFileHeader *hdr)
> @@ -331,7 +331,7 @@ static void argo_asf_write_file_header(const ArgoASFFileHeader *fhdr, AVIOContex
>     avio_wl16( pb, fhdr->version_minor);
>     avio_wl32( pb, fhdr->num_chunks);
>     avio_wl32( pb, fhdr->chunk_offset);
> -    avio_write(pb, fhdr->name, sizeof(fhdr->name));
> +    avio_write(pb, fhdr->name, ASF_NAME_SIZE);
> }
> 
> static void argo_asf_write_chunk_header(const ArgoASFChunkHeader *ckhdr, AVIOContext *pb)
> @@ -368,7 +368,7 @@ static int argo_asf_write_header(AVFormatContext *s)
>     } else {
>         len = end - name;
>     }
> -    memcpy(fhdr.name, name, FFMIN(len, sizeof(fhdr.name)));
> +    memcpy(fhdr.name, name, FFMIN(len, ASF_NAME_SIZE));
> 
>     chdr.num_blocks    = 0;
>     chdr.num_samples   = ASF_SAMPLE_COUNT;
> diff --git a/libavformat/argo_asf.h b/libavformat/argo_asf.h
> index e65125fb79..1fab31a90b 100644
> --- a/libavformat/argo_asf.h
> +++ b/libavformat/argo_asf.h
> @@ -33,6 +33,7 @@
> #define ASF_CHUNK_HEADER_SIZE   20
> #define ASF_SAMPLE_COUNT        32
> #define ASF_MIN_BUFFER_SIZE     FFMAX(ASF_FILE_HEADER_SIZE, ASF_CHUNK_HEADER_SIZE)
> +#define ASF_NAME_SIZE           8
> 
> typedef struct ArgoASFFileHeader {
>     uint32_t    magic;          /*< Magic Number, {'A', 'S', 'F', '\0'} */
> @@ -40,7 +41,7 @@ typedef struct ArgoASFFileHeader {
>     uint16_t    version_minor;  /*< File Minor Version. */
>     uint32_t    num_chunks;     /*< No. chunks in the file. */
>     uint32_t    chunk_offset;   /*< Offset to the first chunk from the start of the file. */
> -    int8_t      name[8];        /*< Name. */
> +    char        name[ASF_NAME_SIZE + 1]; /*< Name, +1 for NULL-terminator. */
> } ArgoASFFileHeader;


I failed to see why null-terminator is needed from the commit message or from the source code.

> 
> typedef struct ArgoASFChunkHeader {
> -- 
> 2.31.1
> 
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