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[FFmpeg-devel] lavc/pcm-bluray: Do not use incompatible pointers on big-endian.

Message ID CAB0OVGrpN9PodR-cV1HsY0vH6Ve28W142+urOEAbpNodwCOgVQ@mail.gmail.com
State Superseded
Headers show

Commit Message

Carl Eugen Hoyos Nov. 1, 2017, 5:25 p.m. UTC 
2017-11-01 18:16 GMT+01:00 Hendrik Leppkes <h.leppkes@gmail.com>:
> On Wed, Nov 1, 2017 at 5:16 PM, Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:
>> Hi!
>>
>> Attached patch silences two gcc warnings, no sample for odd channel count found.
>>
>>  #if HAVE_BIGENDIAN
>> -                    bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
>> -                    dst16 += avctx->channels;
>> +                    uint8_t *dst = frame->data[0];
>> +                    bytestream2_get_buffer(&gb, frame->data[0], avctx->channels * 2);
>> +                    dst += avctx->channels * 2;
>>  #else
>>                      channel = avctx->channels;
>>                      do {
>
> This hunk seems fishy. dst is only ever set, never read, and this code
> is executed in a loop but always writes to the same position.

I had sent the wrong version, please review this one.

Thank you, Carl Eugen

Comments

Hendrik Leppkes Nov. 1, 2017, 5:31 p.m. UTC | #1 
On Wed, Nov 1, 2017 at 6:25 PM, Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:
> 2017-11-01 18:16 GMT+01:00 Hendrik Leppkes <h.leppkes@gmail.com>:
>> On Wed, Nov 1, 2017 at 5:16 PM, Carl Eugen Hoyos <ceffmpeg@gmail.com> wrote:
>>> Hi!
>>>
>>> Attached patch silences two gcc warnings, no sample for odd channel count found.
>>>
>>>  #if HAVE_BIGENDIAN
>>> -                    bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
>>> -                    dst16 += avctx->channels;
>>> +                    uint8_t *dst = frame->data[0];
>>> +                    bytestream2_get_buffer(&gb, frame->data[0], avctx->channels * 2);
>>> +                    dst += avctx->channels * 2;
>>>  #else
>>>                      channel = avctx->channels;
>>>                      do {
>>
>> This hunk seems fishy. dst is only ever set, never read, and this code
>> is executed in a loop but always writes to the same position.
>
> I had sent the wrong version, please review this one.
>

That still won't work, dst is declared within the loop, so its reset
back to the start at the beginning of the frame each iteration.

- Hendrik
diff mbox

Patch

From 8a2b3dd7be86c0494cb2f09088fb1ad92e910571 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffmpeg@gmail.com>
Date: Wed, 1 Nov 2017 18:24:15 +0100
Subject: [PATCH] lavc/pcm-bluray: Do not use incompatible pointers on
 big-endian.

Fixes the following gcc warnings:
libavcodec/pcm-bluray.c:172:45: warning: passing argument 2 of 'bytestream2_get_buffer' from incompatible pointer type
libavcodec/pcm-bluray.c:192:49: warning: passing argument 2 of 'bytestream2_get_buffer' from incompatible pointer type
---
 libavcodec/pcm-bluray.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/libavcodec/pcm-bluray.c b/libavcodec/pcm-bluray.c
index 517d7b5..8f961c3 100644
--- a/libavcodec/pcm-bluray.c
+++ b/libavcodec/pcm-bluray.c
@@ -169,7 +169,7 @@  static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data,
             samples *= num_source_channels;
             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 #if HAVE_BIGENDIAN
-                bytestream2_get_buffer(&gb, dst16, buf_size);
+                bytestream2_get_buffer(&gb, frame->data[0], buf_size);
 #else
                 do {
                     *dst16++ = bytestream2_get_be16u(&gb);
@@ -189,8 +189,9 @@  static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data,
             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
                 do {
 #if HAVE_BIGENDIAN
-                    bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
-                    dst16 += avctx->channels;
+                    uint8_t *dst = frame->data[0];
+                    bytestream2_get_buffer(&gb, dst, avctx->channels * 2);
+                    dst += avctx->channels * 2;
 #else
                     channel = avctx->channels;
                     do {
-- 
1.7.10.4