在 2015/3/15 20:38, Michael Niedermayer 写道:
> On Sun, Mar 15, 2015 at 04:46:22PM +0800, zhaoxiu.zeng wrote:
>> From 60cdc9161881cdf86e428a0d6812785938ae6667 Mon Sep 17 00:00:00 2001
>> From: Zeng Zhaoxiu <zhaoxiu.z...@gmail.com>
>> Date: Sun, 15 Mar 2015 11:56:53 +0800
>> Subject: [PATCH 2/7] avformat/mpegvideodec: use avpriv_find_start_code in
>> mpegvideo_probe()
>>
>> Signed-off-by: Zeng Zhaoxiu <zhaoxiu.z...@gmail.com>
>> ---
>> libavformat/mpegvideodec.c | 34 ++++++++++++++++------------------
>> 1 file changed, 16 insertions(+), 18 deletions(-)
>>
>> diff --git a/libavformat/mpegvideodec.c b/libavformat/mpegvideodec.c
>> index ade76d8..c2fa6c2 100644
>> --- a/libavformat/mpegvideodec.c
>> +++ b/libavformat/mpegvideodec.c
>> @@ -24,6 +24,7 @@
>> #include "rawdec.h"
>>
>> #include "libavutil/intreadwrite.h"
>> +#include "libavcodec/internal.h"
>>
>> #define SEQ_START_CODE 0x000001b3
>> #define GOP_START_CODE 0x000001b8
>> @@ -37,33 +38,30 @@ static int mpegvideo_probe(AVProbeData *p)
>> {
>> uint32_t code= -1;
>> int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0;
>> - int i, j;
>> + const uint8_t *ptr = p->buf, *end = ptr + p->buf_size;
>> uint32_t last = 0;
>> + int j;
>>
>> - for(i=0; i<p->buf_size; i++){
>> - code = (code<<8) + p->buf[i];
>> + while (ptr < end) {
>> + ptr = avpriv_find_start_code(ptr, end, &code);
>> if ((code & 0xffffff00) == 0x100) {
>> - switch(code){
>> + switch (code) {
>> case SEQ_START_CODE:
>> - if (!(p->buf[i+1+3+1+2] & 0x20))
>> + if (!(ptr[3 + 1 + 2] & 0x20))
>> break;
>> - j = i;
>> - if (p->buf[j+8] & 2)
>> - j+= 64;
>> - if (j >= p->buf_size)
>> + j = -1 + (ptr[-1 + 8] & 2) * 32;
>> + if (ptr + j >= end)
>> break;
>> - if (p->buf[j+8] & 1)
>> - j+= 64;
>> - if (j >= p->buf_size)
>> + j += (ptr[j + 8] & 1) * 64;
>> + if (ptr + j >= end)
>> break;
>> - if (AV_RB24(p->buf + j + 9) & 0xFFFFFE)
>> + if (AV_RB24(ptr + j + 9) & 0xFFFFFE)
>> break;
>> seq++;
>> - break;
>> - case PICTURE_START_CODE: pic++; break;
>> + break;
>> + case PICTURE_START_CODE: pic++; break;
>> case PACK_START_CODE: pspack++; break;
>> - case 0x1b6:
>> - res++; break;
>> + case 0x1b6: res++; break;
>> }
>> if (code >= SLICE_START_CODE && code <= 0x1af) {
>> if (last >= SLICE_START_CODE && last <= 0x1af) {
>
> cleaned up and applied
>
> also please do not mix unrelated cosmetic changes in the code
> see for example the diff with these cosmetics removed, which i applied
> its much more readable: (this is important for being reviewable)
>
I see! Thanks!
> diff --git a/libavformat/mpegvideodec.c b/libavformat/mpegvideodec.c
> index ade76d86..5ea5569 100644
> --- a/libavformat/mpegvideodec.c
> +++ b/libavformat/mpegvideodec.c
> @@ -24,6 +24,7 @@
> #include "rawdec.h"
>
> #include "libavutil/intreadwrite.h"
> +#include "libavcodec/internal.h"
>
> #define SEQ_START_CODE 0x000001b3
> #define GOP_START_CODE 0x000001b8
> @@ -37,26 +38,27 @@ static int mpegvideo_probe(AVProbeData *p)
> {
> uint32_t code= -1;
> int pic=0, seq=0, slice=0, pspack=0, vpes=0, apes=0, res=0, sicle=0;
> - int i, j;
> + const uint8_t *ptr = p->buf, *end = ptr + p->buf_size;
> uint32_t last = 0;
> + int j;
>
> - for(i=0; i<p->buf_size; i++){
> - code = (code<<8) + p->buf[i];
> + while (ptr < end) {
> + ptr = avpriv_find_start_code(ptr, end, &code);
> if ((code & 0xffffff00) == 0x100) {
> switch(code){
> case SEQ_START_CODE:
> - if (!(p->buf[i+1+3+1+2] & 0x20))
> + if (!(ptr[3 + 1 + 2] & 0x20))
> break;
> - j = i;
> - if (p->buf[j+8] & 2)
> + j = -1;
> + if (ptr[j + 8] & 2)
> j+= 64;
> - if (j >= p->buf_size)
> + if (ptr + j >= end)
> break;
> - if (p->buf[j+8] & 1)
> + if (ptr[j + 8] & 1)
> j+= 64;
> - if (j >= p->buf_size)
> + if (ptr + j >= end)
> break;
> - if (AV_RB24(p->buf + j + 9) & 0xFFFFFE)
> + if (AV_RB24(ptr + j + 9) & 0xFFFFFE)
> break;
> seq++;
> break;
>
>
> [...]
>
>
>
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